systemd Changelog

What's new in systemd 242

Apr 12, 2019

* In .link files, MACAddressPolicy=persistent (the default) is changed
to cover more devices. For devices like bridges, tun, tap, bond, and
similar interfaces that do not have other identifying information,
the interface name is used as the basis for persistent seed for MAC
and IPv4LL addresses. The way that devices that were handled
previously is not changed, and this change is about covering more
devices then previously by the "persistent" policy.
MACAddressPolicy=random may be used to force randomized MACs and
IPv4LL addresses for a device if desired.
Hint: the log output from udev (at debug level) was enhanced to
clarify what policy is followed and which attributes are used.
`SYSTEMD_LOG_LEVEL=debug udevadm test-builtin net_setup_link /sys/class/net/`
may be used to view this.
* The .device units generated by systemd-fstab-generator and other
generators do not automatically pull in the corresponding .mount unit
as a Wants= dependency. This means that simply plugging in the device
will not cause the mount unit to be started automatically. But please
note that the mount unit may be started for other reasons, in
particular if it is part of local-fs.target, and any unit which
(transitively) depends on local-fs.target is started.
* networkctl list/status/lldp now accept globbing wildcards for network
interface names to match against all existing interfaces.
* The $PIDFILE environment variable is set to point the absolute path
configured with PIDFile= for processes of that service.
* The fallback DNS server list was augmented with Cloudflare public DNS
servers. Use `-Ddns-servers=` to set a different fallback.
* A new special target usb-gadget.target will be started automatically
when a USB Device Controller is detected (which means that the system
is a USB peripheral).
* A new unit setting CPUQuotaPeriodSec= assigns the time period
relatively to which the CPU time quota specified by CPUQuota= is
measured.
* A new unit setting ProtectHostname= may be used to prevent services
from modifying hostname information (even if they otherwise would
have privileges to do so).
* A new unit setting NetworkNamespacePath= may be used to specify a
namespace for service or socket units through a path referring to a
Linux network namespace pseudo-file.
* The PrivateNetwork= setting and JoinsNamespaceOf= dependencies now
have an effect on .socket units: when used the listening socket is
created within the configured network namespace instead of the host
namespace.
* ExecStart= command lines in unit files may now be prefixed with ':'
in which case environment variable substitution is
disabled. (Supported for the other ExecXYZ= settings, too.)
* .timer units gained two new boolean settings OnClockChange= and
OnTimezoneChange= which may be used to also trigger a unit when the
system clock is changed or the local timezone is
modified. systemd-run has been updated to make these options easily
accessible from the command line for transient timers.
* Two new conditions for units have been added: ConditionMemory= may be
used to conditionalize a unit based on installed system
RAM. ConditionCPUs= may be used to conditionalize a unit based on
install CPU cores.
* The @default system call filter group understood by SystemCallFilter=
has been updated to include the new rseq() system call introduced in
kernel 4.15.
* A new time-set.target has been added that indicates that the system
time has been set from a local source (possibly imprecise). The
existing time-sync.target is stronger and indicates that the time has
been synchronized with a precise external source. Services where
approximate time is sufficient should use the new target.
* "systemctl start" (and related commands) learnt a new
--show-transaction option. If specified brief information about all
jobs queued because of the requested operation is shown.
* systemd-networkd recognizes a new operation state 'enslaved', used
(instead of 'degraded' or 'carrier') for interfaces which form a
bridge, bond, or similar, and an new 'degraded-carrier' operational
state used for the bond or bridge master interface when one of the
enslaved devices is not operational.
* .network files learnt the new IgnoreCarrierLoss= option for leaving
networks configured even if the carrier is lost.
* The RequiredForOnline= setting in .network files may now specify a
minimum operational state required for the interface to be considered
"online" by systemd-networkd-wait-online. Related to this
systemd-networkd-wait-online gained a new option --operational-state=
to configure the same, and its --interface= option was updated to
optionally also take an operational state specific for an interface.
* systemd-networkd-wait-online gained a new setting --any for waiting
for only one of the requested interfaces instead of all of them.
* systemd-networkd now implements L2TP tunnels.
* Two new .network settings UseAutonomousPrefix= and UseOnLinkPrefix=
may be used to cause autonomous and onlink prefixes received in IPv6
Router Advertisements to be ignored.
* New MulticastFlood=, NeighborSuppression=, and Learning= .network
file settings may be used to tweak bridge behaviour.
* The new TripleSampling= option in .network files may be used to
configure CAN triple sampling.
* A new .netdev settings PrivateKeyFile= and PresharedKeyFile= may be
used to point to private or preshared key for a WireGuard interface.
* /etc/crypttab now supports the same-cpu-crypt and
submit-from-crypt-cpus options to tweak encryption work scheduling
details.
* systemd-tmpfiles will now take a BSD file lock before operating on a
contents of directory. This may be used to temporarily exclude
directories from aging by taking the same lock (useful for example
when extracting a tarball into /tmp or /var/tmp as a privileged user,
which might create files with really old timestamps, which
nevertheless should not be deleted). For further details, see:
https://systemd.io/TEMPORARY_DIRECTORIES
* systemd-tmpfiles' h line type gained support for the
FS_PROJINHERIT_FL ('P') file attribute (introduced in kernel 4.5),
controlling project quota inheritance.
* sd-boot and bootctl now implement support for an Extended Boot Loader
(XBOOTLDR) partition, that is intended to be mounted to /boot, in
addition to the ESP partition mounted to /efi or /boot/efi.
Configuration file fragments, kernels, initrds and other EFI images
to boot will be loaded from both the ESP and XBOOTLDR partitions.
The XBOOTLDR partition was previously described by the Boot Loader
Specification, but implementation was missing in sd-boot. Support for
this concept allows using the sd-boot boot loader in more
conservative scenarios where the boot loader itself is placed in the
ESP but the kernels to boot (and their metadata) in a separate
partition.
* A system may now be booted with systemd.volatile=overlay on the
kernel command line, which causes the root file system to be set up
an overlayfs mount combining the root-only root directory with a
writable tmpfs. In this setup, the underlying root device is not
modified, and any changes are lost at reboot.
* Similar, systemd-nspawn can now boot containers with a volatile
overlayfs root with the new --volatile=overlay switch.
* systemd-nspawn can now consume OCI runtime bundles using a new
--oci-bundle= option. This implementation is fully usable, with most
features in the specification implemented, but since this a lot of
new code and functionality, this feature should most likely not
be used in production yet.
* systemd-nspawn now supports various options described by the OCI
runtime specification on the command-line and in .nspawn files:
--inaccessible=/Inaccessible= may be used to mask parts of the file
system tree, --console=/--pipe may be used to configure how standard
input, output, and error are set up.
* busctl learned the `emit` verb to generate D-Bus signals.
* systemd-analyze cat-config may be used to gather and display
configuration spread over multiple files, for example system and user
presets, tmpfiles.d, sysusers.d, udev rules, etc.
* systemd-analyze calendar now takes an optional new parameter
--iterations= which may be used to show a maximum number of iterations
the specified expression will elapse next.
* The sd-bus C API gained support for naming method parameters in the
introspection data.
* systemd-logind gained D-Bus APIs to specify the "reboot parameter"
the reboot() system call expects.
* journalctl learnt a new --cursor-file= option that points to a file
from which a cursor should be loaded in the beginning and to which
the updated cursor should be stored at the end.
* ACRN hypervisor and Windows Subsystem for Linux (WSL) are now
detected by systemd-detect-virt (and may also be used in
ConditionVirtualization=).
* The behaviour of systemd-logind may now be modified with environment
variables $SYSTEMD_REBOOT_TO_FIRMWARE_SETUP,
$SYSTEMD_REBOOT_TO_BOOT_LOADER_MENU, and
$SYSTEMD_REBOOT_TO_BOOT_LOADER_ENTRY. They cause logind to either
skip the relevant operation completely (when set to false), or to
create a flag file in /run/systemd (when set to true), instead of
actually commencing the real operation when requested. The presence
of /run/systemd/reboot-to-firmware-setup,
/run/systemd/reboot-to-boot-loader-menu, and
/run/systemd/reboot-to-boot-loader-entry, may be used by alternative
boot loader implementations to replace some steps logind performs
during reboot with their own operations.
* systemctl can be used to request a reboot into the boot loader menu
or a specific boot loader entry with the new --boot-load-menu= and
--boot-loader-entry= options to a reboot command. (This requires a
boot loader that supports this, for example sd-boot.)
* kernel-install will no longer unconditionally create the output
directory (e.g. /efi//) for boot loader
snippets, but will do only if the machine-specific parent directory
(i.e. /efi//) already exists. bootctl has been modified
to create this parent directory during sd-boot installation.
This makes it easier to use kernel-install with plugins which support
a different layout of the bootloader partitions (for example grub2).
* During package installation (with `ninja install`), we would create
symlinks for systemd-networkd.service, systemd-networkd.socket,
systemd-resolved.service, remote-cryptsetup.target, remote-fs.target,
systemd-networkd-wait-online.service, and systemd-timesyncd.service
in /etc, as if `systemctl enable` was called for those units, to make
the system usable immediately after installation. Now this is not
done anymore, and instead calling `systemctl preset-all` is
recommended after the first installation of systemd.
* A new boolean sandboxing option RestrictSUIDSGID= has been added that
is built on seccomp. When turned on creation of SUID/SGID files is
prohibited.
* The NoNewPrivileges= and the new RestrictSUIDSGID= options are now
implied if DynamicUser= is turned on for a service. This hardens
these services, so that they neither can benefit from nor create
SUID/SGID executables. This is a minor compatibility breakage, given
that when DynamicUser= was first introduced SUID/SGID behaviour was
unaffected. However, the security benefit of these two options is
substantial, and the setting is still relatively new, hence we opted
to make it mandatory for services with dynamic users.

New in systemd 241 (Feb 14, 2019)

The default locale can now be configured at compile time. Otherwise, a suitable default will be selected automatically (one of C.UTF-8, en_US.UTF-8, and C).
The version string shown by systemd and other tools now includes the git commit hash when built from git. An override may be specified during compilation, which is intended to be used by distributions to include the package release information.
systemd-cat can now filter standard input and standard error streams for different syslog priorities using the new --stderr-priority= option.
systemd-journald and systemd-journal-remote reject entries which contain too many fields (CVE-2018-16865) and set limits on the process' command line length (CVE-2018-16864).
$DBUS_SESSION_BUS_ADDRESS environment variable is set by pam_systemd again.
A new network device NamePolicy "keep" is implemented for link files, and used by default in 99-default.link (the fallback configuration provided by systemd). With this policy, if the network device name was already set by userspace, the device will not be renamed again. This matches the naming scheme that was implemented before systemd-240. If naming-scheme < 240 is specified, the "keep" policy is also enabled by default, even if not specified. Effectively, this means that if naming-scheme >= 240 is specified, network devices will be renamed according to the configuration, even if they have been renamed already, if "keep" is not specified as the naming policy in the .link file. The 99-default.link file provided by systemd includes "keep" for backwards compatibility, but it is recommended for user installed .link files to *not* include it.
The "kernel" policy, which keeps kernel names declared to be "persistent", now works again as documented.
kernel-install script now optionally takes the paths to one or more initrd files, and passes them to all plugins.
The mincore() system call has been dropped from the @system-service system call filter group, as it is pretty exotic and may potentially used for side-channel attacks.
-fPIE is dropped from compiler and linker options. Please specify -Db_pie=true option to meson to build position-independent executables. Note that the meson option is supported since meson-0.49.
The fs.protected_regular and fs.protected_fifos sysctls, which were added in Linux 4.19 to make some data spoofing attacks harder, are now enabled by default. While this will hopefully improve the security of most installations, it is technically a backwards incompatible change; to disable these sysctls again, place the following lines in /etc/sysctl.d/60-protected.conf or a similar file...
fs.protected_regular = 0
fs.protected_fifos = 0
Note that the similar hardlink and symlink protection has been enabled since v199, and may be disabled likewise.
The files read from the EnvironmentFile= setting in unit files now parse backslashes inside quotes literally, matching the behaviour of POSIX shells.
udevadm trigger, udevadm control, udevadm settle and udevadm monitor now automatically become NOPs when run in a chroot() environment.
The tmpfiles.d/ "C" line type will now copy directory trees not only when the destination is so far missing, but also if it already exists as a directory and is empty. This is useful to cater for systems where directory trees are put together from multiple separate mount points but otherwise empty.
A new function sd_bus_close_unref() (and the associated sd_bus_close_unrefp()) has been added to libsystemd, that combines sd_bus_close() and sd_bus_unref() in one.
udevadm control learnt a new option for --ping for testing whether a systemd-udevd instance is running and reacting.

New in systemd 237 (Jan 30, 2018)

Some keyboards come with a zoom see-saw or rocker which until now got
mapped to the Linux "zoomin/out" keys in hwdb. However, these
keycodes are not recognized by any major desktop. They now produce
Up/Down key events so that they can be used for scrolling.
* INCOMPATIBILITY: systemd-tmpfiles' "f" lines changed behaviour
slightly: previously, if an argument was specified for lines of this
type (i.e. the right-most column was set) this string was appended to
existing files each time systemd-tmpfiles was run. This behaviour was
different from what the documentation said, and not particularly
useful, as repeated systemd-tmpfiles invocations would not be
idempotent and grow such files without bounds. With this release
behaviour has been altered slightly, to match what the documentation
says: lines of this type only have an effect if the indicated files
don't exist yet, and only then the argument string is written to the
file.
* FUTURE INCOMPATIBILITY: In systemd v238 we intend to slightly change
systemd-tmpfiles behaviour: previously, read-only files owned by root
were always excluded from the file "aging" algorithm (i.e. the
automatic clean-up of directories like /tmp based on
atime/mtime/ctime). We intend to drop this restriction, and age files
by default even when owned by root and read-only. This behaviour was
inherited from older tools, but there have been requests to remove
it, and it's not obvious why this restriction was made in the first
place. Please speak up now, if you are aware of software that reqires
this behaviour, otherwise we'll remove the restriction in v238.
* A new environment variable $SYSTEMD_OFFLINE is now understood by
systemctl. It takes a boolean argument. If on, systemctl assumes it
operates on an "offline" OS tree, and will not attempt to talk to the
service manager. Previously, this mode was implicitly enabled if a
chroot() environment was detected, and this new environment variable
now provides explicit control.
* .path and .socket units may now be created transiently, too.
Previously only service, mount, automount and timer units were
supported as transient units. The systemd-run tool has been updated
to expose this new functionality, you may hence use it now to bind
arbitrary commands to path or socket activation on-the-fly from the
command line. Moreover, almost all properties are now exposed for the
unit types that already supported transient operation.
* The systemd-mount command gained support for a new --owner= parameter
which takes a user name, which is then resolved and included in uid=
and gid= mount options string of the file system to mount.
* A new unit condition ConditionControlGroupController= has been added
that checks whether a specific cgroup controller is available.
* Unit files, udev's .link files, and systemd-networkd's .netdev and
.network files all gained support for a new condition
ConditionKernelVersion= for checking against specific kernel
versions.
* In systemd-networkd, the [IPVLAN] section in .netdev files gained
support for configuring device flags in the Flags= setting. In the
same files, the [Tunnel] section gained support for configuring
AllowLocalRemote=. The [Route] section in .network files gained
support for configuring InitialCongestionWindow=,
InitialAdvertisedReceiveWindow= and QuickAck=. The [DHCP] section now
understands RapidCommit=.
* systemd-networkd's DHCPv6 support gained support for Prefix
Delegation.
* sd-bus gained support for a new "watch-bind" feature. When this
feature is enabled, an sd_bus connection may be set up to connect to
an AF_UNIX socket in the file system as soon as it is created. This
functionality is useful for writing early-boot services that
automatically connect to the system bus as soon as it is started,
without ugly time-based polling. systemd-networkd and
systemd-resolved have been updated to make use of this
functionality. busctl exposes this functionality in a new
--watch-bind= command line switch.
* sd-bus will now optionally synthesize a local "Connected" signal as
soon as a D-Bus connection is set up fully. This message mirrors the
already existing "Disconnected" signal which is synthesized when the
connection is terminated. This signal is generally useful but
particularly handy in combination with the "watch-bind" feature
described above. Synthesizing of this message has to be requested
explicitly through the new API call sd_bus_set_connected_signal(). In
addition a new call sd_bus_is_ready() has been added that checks
whether a connection is fully set up (i.e. between the "Connected" and
"Disconnected" signals).
* sd-bus gained two new calls sd_bus_request_name_async() and
sd_bus_release_name_async() for asynchronously registering bus
names. Similar, there is now sd_bus_add_match_async() for installing
a signal match asynchronously. All of systemd's own services have
been updated to make use of these calls. Doing these operations
asynchronously has two benefits: it reduces the risk of deadlocks in
case of cyclic dependencies between bus services, and it speeds up
service initialization since synchronization points for bus
round-trips are removed.
* sd-bus gained two new calls sd_bus_match_signal() and
sd_bus_match_signal_async(), which are similar to sd_bus_add_match()
and sd_bus_add_match_async() but instead of taking a D-Bus match
string take match fields as normal function parameters.
* sd-bus gained two new calls sd_bus_set_sender() and
sd_bus_message_set_sender() for setting the sender name of outgoing
messages (either for all outgoing messages or for just one specific
one). These calls are only useful in direct connections as on
brokered connections the broker fills in the sender anyway,
overwriting whatever the client filled in.
* sd-event gained a new pseudo-handle that may be specified on all API
calls where an "sd_event*" object is expected: SD_EVENT_DEFAULT. When
used this refers to the default event loop object of the calling
thread. Note however that this does not implicitly allocate one —
which has to be done prior by using sd_event_default(). Similarly
sd-bus gained three new pseudo-handles SD_BUS_DEFAULT,
SD_BUS_DEFAULT_USER, SD_BUS_DEFAULT_SYSTEM that may be used to refer
to the default bus of the specified type of the calling thread. Here
too this does not implicitly allocate bus connection objects, this
has to be done prior with sd_bus_default() and friends.
* sd-event gained a new call pair
sd_event_source_{get|set}_io_fd_own(). This may be used to request
automatic closure of the file descriptor an IO event source watches
when the event source is destroyed.
* systemd-networkd gained support for natively configuring WireGuard
connections.
* In previous versions systemd synthesized user records both for the
"nobody" (UID 65534) and "root" (UID 0) users in nss-systemd and
internally. In order to simplify distribution-wide renames of the
"nobody" user (like it is planned in Fedora: nfsnobody → nobody), a
new transitional flag file has been added: if
/etc/systemd/dont-synthesize-nobody exists synthesizing of the 65534
user and group record within the systemd codebase is disabled.
* systemd-notify gained a new --uid= option for selecting the source
user/UID to use for notification messages sent to the service
manager.
* journalctl gained a new --grep= option to list only entries in which
the message matches a certain pattern. By default matching is case
insensitive if the pattern is lowercase, and case sensitive
otherwise. Option --case-sensitive=yes|no can be used to override
this an specify case sensitivity or case insensitivity.
* There's now a "systemd-analyze service-watchdogs" command for printing
the current state of the service runtime watchdog, and optionally
enabling or disabling the per-service watchdogs system-wide if given a
boolean argument (i.e. the concept you configure in WatchdogSec=), for
debugging purposes. There's also a kernel command line option
systemd.service_watchdogs= for controlling the same.
* Two new "log-level" and "log-target" options for systemd-analyze were
addded that merge the now deprecated get-log-level, set-log-level and
get-log-target, set-log-target pairs. The deprecated options are still
understood for backwards compatibility. The two new options print the
current value when no arguments are given, and set them when a
level/target is given as an argument.
* sysusers.d's "u" lines now optionally accept both a UID and a GID
specification, separated by a ":" character, in order to create users
where UID and GID do not match.

New in systemd 236 (Dec 29, 2017)

The modprobe.d/ drop-in for the bonding.ko kernel module introduced
in v235 has been extended to also set the dummy.ko module option
numdummies=0, preventing the kernel from automatically creating
dummy0. All dummy interfaces must now be explicitly created.
* Unknown '%' specifiers in configuration files are now rejected. This
applies to units and tmpfiles.d configuration. Any percent characters
that are followed by a letter or digit that are not supposed to be
interpreted as the beginning of a specifier should be escaped by
doubling ("%%"). (So "size=5%" is still accepted, as well as
"size=5%,foo=bar", but not "LABEL=x%y%z" since %y and %z are not
valid specifiers today.)
* systemd-resolved now maintains a new dynamic
/run/systemd/resolve/stub-resolv.conf compatibility file. It is
recommended to make /etc/resolv.conf a symlink to it. This file
points at the systemd-resolved stub DNS 127.0.0.53 resolver and
includes dynamically acquired search domains, achieving more correct
DNS resolution by software that bypasses local DNS APIs such as NSS.
* The "uaccess" udev tag has been dropped from /dev/kvm and
/dev/dri/renderD*. These devices now have the 0666 permissions by
default (but this may be changed at build-time). /dev/dri/renderD*
will now be owned by the "render" group along with /dev/kfd.
* "DynamicUser=yes" has been enabled for systemd-timesyncd.service,
systemd-journal-gatewayd.service and
systemd-journal-upload.service. This means "nss-systemd" must be
enabled in /etc/nsswitch.conf to ensure the UIDs assigned to these
services are resolved properly.
* In /etc/fstab two new mount options are now understood:
x-systemd.makefs and x-systemd.growfs. The former has the effect that
the configured file system is formatted before it is mounted, the
latter that the file system is resized to the full block device size
after it is mounted (i.e. if the file system is smaller than the
partition it resides on, it's grown). This is similar to the fsck
logic in /etc/fstab, and pulls in systemd-makefs at .service and
systemd-growfs at .service as necessary, similar to
systemd-fsck at .service. Resizing is currently only supported on ext4
and btrfs.
* In systemd-networkd, the IPv6 RA logic now optionally may announce
DNS server and domain information.
* Support for the LUKS2 on-disk format for encrypted partitions has
been added. This requires libcryptsetup2 during compilation and
runtime.
* The systemd --user instance will now signal "readiness" when its
basic.target unit has been reached, instead of when the run queue ran
empty for the first time.
* Tmpfiles.d with user configuration are now also supported.
systemd-tmpfiles gained a new --user switch, and snippets placed in
~/.config/user-tmpfiles.d/ and corresponding directories will be
executed by systemd-tmpfiles --user running in the new
systemd-tmpfiles-setup.service and systemd-tmpfiles-clean.service
running in the user session.
* Unit files and tmpfiles.d snippets learnt three new % specifiers:
%S resolves to the top-level state directory (/var/lib for the system
instance, $XDG_CONFIG_HOME for the user instance), %C resolves to the
top-level cache directory (/var/cache for the system instance,
$XDG_CACHE_HOME for the user instance), %L resolves to the top-level
logs directory (/var/log for the system instance,
$XDG_CONFIG_HOME/log/ for the user instance). This matches the
existing %t specifier, that resolves to the top-level runtime
directory (/run for the system instance, and $XDG_RUNTIME_DIR for the
user instance).
* journalctl learnt a new parameter --output-fields= for limiting the
set of journal fields to output in verbose and JSON output modes.
* systemd-timesyncd's configuration file gained a new option
RootDistanceMaxSec= for setting the maximum root distance of servers
it'll use, as well as the new options PollIntervalMinSec= and
PollIntervalMaxSec= to tweak the minimum and maximum poll interval.
* bootctl gained a new command "list" for listing all available boot
menu items on systems that follow the boot loader specification.
* systemctl gained a new --dry-run switch that shows what would be done
instead of doing it, and is currently supported by the shutdown and
sleep verbs.
* ConditionSecurity= can now detect the TOMOYO security module.
* Unit file [Install] sections are now also respected in unit drop-in
files. This is intended to be used by drop-ins under /usr/lib/.
* systemd-firstboot may now also set the initial keyboard mapping.
* Udev "changed" events for devices which are exposed as systemd
.device units are now propagated to units specified in
ReloadPropagatedFrom= as reload requests.
* If a udev device has a SYSTEMD_WANTS= property containing a systemd
unit template name (i.e. a name in the form of 'foobar at .service',
without the instance component between the '@' and - the '.'), then
the escaped sysfs path of the device is automatically used as the
instance.
* SystemCallFilter= in unit files has been extended so that an "errno"
can be specified individually for each system call. Example:
SystemCallFilter=~uname:EILSEQ.
* The cgroup delegation logic has been substantially updated. Delegate=
now optionally takes a list of controllers (instead of a boolean, as
before), which lists the controllers to delegate at least.
* The networkd DHCPv6 client now implements the FQDN option (RFC 4704).
* A new LogLevelMax= setting configures the maximum log level any
process of the service may log at (i.e. anything with a lesser
priority than what is specified is automatically dropped). A new
LogExtraFields= setting allows configuration of additional journal
fields to attach to all log records generated by any of the unit's
processes.
* New StandardInputData= and StandardInputText= settings along with the
new option StandardInput=data may be used to configure textual or
binary data that shall be passed to the executed service process via
standard input, encoded in-line in the unit file.
* StandardInput=, StandardOutput= and StandardError= may now be used to
connect stdin/stdout/stderr of executed processes directly with a
file or AF_UNIX socket in the file system, using the new "file:" option.
* A new unit file option CollectMode= has been added, that allows
tweaking the garbage collection logic for units. It may be used to
tell systemd to garbage collect units that have failed automatically
(normally it only GCs units that exited successfully). systemd-run
and systemd-mount expose this new functionality with a new -G option.
* "machinectl bind" may now be used to bind mount non-directories
(i.e. regularfiles, devices, fifos, sockets).
* systemd-analyze gained a new verb "calendar" for validating and
testing calendar time specifications to use for OnCalendar= in timer
units. Besides validating the expression it will calculate the next
time the specified expression would elapse.
* In addition to the pre-existing FailureAction= unit file setting
there's now SuccessAction=, for configuring a shutdown action to
execute when a unit completes successfully. This is useful in
particular inside containers that shall terminate after some workload
has been completed. Also, both options are now supported for all unit
types, not just services.
* networkds's IP rule support gained two new options
IncomingInterface= and OutgoingInterface= for configuring the incoming
and outgoing interfaces of configured rules. systemd-networkd also
gained support for "vxcan" network devices.
* networkd gained a new setting RequiredForOnline=, taking a
boolean. If set, systemd-wait-online will take it into consideration
when determining that the system is up, otherwise it will ignore the
interface for this purpose.
* The sd_notify() protocol gained support for a new operation: with
FDSTOREREMOVE=1 file descriptors may be removed from the per-service
store again, ahead of POLLHUP or POLLERR when they are removed
anyway.
* A new document UIDS-GIDS.md has been added to the source tree, that
documents the UID/GID range and assignment assumptions and
requirements of systemd.
* The watchdog device PID 1 will ping may now be configured through the
WatchdogDevice= configuration file setting, or by setting the
systemd.watchdog_service= kernel commandline option.
* systemd-resolved's gained support for registering DNS-SD services on
the local network using MulticastDNS. Services may either be
registered by dropping in a .dnssd file in /etc/systemd/dnssd/ (or
the same dir below /run, /usr/lib), or through its D-Bus API.
* The sd_notify() protocol can now with EXTEND_TIMEOUT_USEC=microsecond
extend the effective start, runtime, and stop time. The service must
continue to send EXTEND_TIMEOUT_USEC within the period specified to
prevent the service manager from making the service as timedout.
* systemd-resolved's DNSSEC support gained support for RFC 8080
(Ed25519 keys and signatures).
* The systemd-resolve command line tool gained a new set of options
--set-dns=, --set-domain=, --set-llmnr=, --set-mdns=, --set-dnssec=,
--set-nta= and --revert to configure per-interface DNS configuration
dynamically during runtime. It's useful for pushing DNS information
into systemd-resolved from DNS hook scripts that various interface
managing software supports (such as pppd).
* systemd-nspawn gained a new --network-namespace-path= command line
option, which may be used to make a container join an existing
network namespace, by specifying a path to a "netns" file.

New in systemd 234 (Jul 13, 2017)

Meson is now supported as build system in addition to Automake. It is our plan to remove Automake in one of our next releases, so that Meson becomes our exclusive build system. Hence, please start using the Meson build system in your downstream packaging. There's plenty of documentation around how to use Meson, the extremely brief summary:
./autogen.sh && ./configure && make && sudo make install
becomes:
meson build && ninja -C build && sudo ninja -C build install
Unit files gained support for a new JobRunningTimeoutUSec= setting, which permits configuring a timeout on the time a job is running. This is particularly useful for setting timeouts on jobs for .device units.
Unit files gained two new options ConditionUser= and ConditionGroup= for conditionalizing units based on the identity of the user/group running a systemd user instance.
systemd-networkd now understands a new FlowLabel= setting in the [VXLAN] section of .network files, as well as a Priority= in [Bridge], GVRP= + MVRP= + LooseBinding= + ReorderHeader= in [VLAN] and GatewayOnlink= + IPv6Preference= + Protocol= in [Route]. It also gained support for configuration of GENEVE links, and IPv6 address labels. The [Network] section gained the new IPv6ProxyNDP= setting.
.link files now understand a new Port= setting.
systemd-networkd's DHCP support gained support for DHCP option 119 (domain search list).
systemd-networkd gained support for serving IPv6 address ranges using the Router Advertisment protocol. The new .network configuration section [IPv6Prefix] may be used to configure the ranges to serve. This is implemented based on a new, minimal, native server implementation of RA.
journalctl's --output= switch gained support for a new parameter "short-iso-precise" for a mode where timestamps are shown as precise ISO date values.
systemd-udevd's "net_id" builtin may now generate stable network interface names from IBM PowerVM VIO devices as well as ACPI platform devices.
MulticastDNS support in systemd-resolved may now be explicitly enabled/disabled using the new MulticastDNS= configuration file option.
systemd-resolved may now optionally use libidn2 instead of the libidn for processing internationalized domain names. Support for libidn2 should be considered experimental and should not be enabled by default yet.
"machinectl pull-tar" and related call may now do verification of downloaded images using SUSE-style .sha256 checksum files in addition to the already existing support for validating using Ubuntu-style SHA256SUMS files.
sd-bus gained support for a new sd_bus_message_appendv() call which is va_list equivalent of sd_bus_message_append().
sd-boot gained support for validating images using SHIM/MOK.
The SMACK code learnt support for "onlycap".
systemd-mount --umount is now much smarter in figuring out how to properly unmount a device given its mount or device path.
The code to call libnss_dns as a fallback from libnss_resolve when the communication with systemd-resolved fails was removed. This fallback was redundant and interfered with the [!UNAVAIL=return] suffix. See nss-resolve(8) for the recommended configuration.
systemd-logind may now be restarted without losing state. It stores the file descriptors for devices it manages in the system manager using the FDSTORE= mechanism. Please note that further changes in other components may be required to make use of this (for example Xorg has code to listen for stops of systemd-logind and terminate itself when logind is stopped or restarted, in order to avoid using stale file descriptors for graphical devices, which is now counterproductive and must be reverted in order for restarts of systemd-logind to be safe. See https://cgit.freedesktop.org/xorg/xserver/commit/?id=dc48bd653c7e101.)
All kernel install plugins are called with the environment variable KERNEL_INSTALL_MACHINE_ID which is set to the machine ID given by /etc/machine-id. If the file is missing or empty, the variable is empty and BOOT_DIR_ABS is the path of a temporary directory which is removed after all the plugins exit. So, if KERNEL_INSTALL_MACHINE_ID is empty, all plugins should not put anything in BOOT_DIR_ABS.

New in systemd 233 (Mar 1, 2017)

The "hybrid" control group mode has been modified to improve compatibility with "legacy" cgroups-v1 setups. Specifically, the "hybrid" setup of /sys/fs/cgroup is now pretty much identical to "legacy" (including /sys/fs/cgroup/systemd as "name=systemd" named cgroups-v1 hierarchy), the only externally visible change being that the cgroups-v2 hierarchy is also mounted, to /sys/fs/cgroup/unified. This should provide a large degree of compatibility with "legacy" cgroups-v1, while taking benefit of the better management capabilities of cgroups-v2.
The default control group setup mode may be selected both a boot-time via a set of kernel command line parameters (specifically: systemd.unified_cgroup_hierarchy= and systemd.legacy_systemd_cgroup_controller=), as well as a compile-time default selected on the configure command line (--with-default-hierarchy=). The upstream default is "hybrid" (i.e. the cgroups-v1 + cgroups-v2 mixture discussed above) now, but this will change in a future systemd version to be "unified" (pure cgroups-v2 mode). The third option for the compile time option is "legacy", to enter pure cgroups-v1 mode. We recommend downstream distributions to default to "hybrid" mode for release distributions, starting with v233. We recommend "unified" for development distributions (specifically: distributions such as Fedora's rawhide) as that's where things are headed in the long run. Use "legacy" for greatest stability and compatibility only.
Note one current limitation of "unified" and "hybrid" control group setup modes: the kernel currently does not permit the systemd --user instance (i.e. unprivileged code) to migrate processes between two disconnected cgroup subtrees, even if both are managed and owned by the user. This effectively means "systemd-run --user --scope" doesn't work when invoked from outside of any "systemd --user" service or scope. Specifically, it is not supported from session scopes. We are working on fixing this in a future systemd version. (See #3388 for further details about this.)
DBus policy files are now installed into /usr rather than /etc. Make sure your system has dbus >= 1.9.18 running before upgrading to this version, or override the install path with --with-dbuspolicydir= .
All python scripts shipped with systemd (specifically: the various tests written in Python) now require Python 3.
systemd unit tests can now run standalone (without the source or build directories), and can be installed into /usr/lib/systemd/tests/ with 'make install-tests'.
Note that from this version on, CONFIG_CRYPTO_USER_API_HASH, CONFIG_CRYPTO_HMAC and CONFIG_CRYPTO_SHA256 need to be enabled in the kernel.
Support for the %c, %r, %R specifiers in unit files has been removed. Specifiers are not supposed to be dependent on configuration in the unit file itself (so that they resolve the same regardless where used in the unit files), but these specifiers were influenced by the Slice= option.
The shell invoked by debug-shell.service now defaults to /bin/sh in all cases. If distributions want to use a different shell for this purpose (for example Fedora's /sbin/sushell) they need to specify this explicitly at configure time using --with-debug-shell=.
The confirmation spawn prompt has been reworked to offer the following choices:
(c)ontinue, proceed without asking anymore (D)ump, show the state of the unit (f)ail, don't execute the command and pretend it failed (h)elp (i)nfo, show a short summary of the unit (j)obs, show jobs that are in progress (s)kip, don't execute the command and pretend it succeeded (y)es, execute the command
The 'n' choice for the confirmation spawn prompt has been removed, because its meaning was confusing.
The prompt may now also be redirected to an alternative console by specifying the console as parameter to systemd.confirm_spawn=.
Services of Type=notify require a READY=1 notification to be sent during startup. If no such message is sent, the service now fails, even if the main process exited with a successful exit code.
Services that fail to start up correctly now always have their ExecStopPost= commands executed. Previously, they'd enter "failed" state directly, without executing these commands.
The option MulticastDNS= of network configuration files has acquired an actual implementation. With MulticastDNS=yes a host can resolve names of remote hosts and reply to mDNS A and AAAA requests.
When units are about to be started an additional check is now done to ensure that all dependencies of type BindsTo= (when used in combination with After=) have been started.
systemd-analyze gained a new verb "syscall-filter" which shows which system call groups are defined for the SystemCallFilter= unit file setting, and which system calls they contain.
A new system call filter group "@filesystem" has been added, consisting of various file system related system calls. Group "@reboot" has been added, covering reboot, kexec and shutdown related calls. Finally, group "@swap" has been added covering swap configuration related calls.
A new unit file option RestrictNamespaces= has been added that may be used to restrict access to the various process namespace types the Linux kernel provides. Specifically, it may be used to take away the right for a service unit to create additional file system, network, user, and other namespaces. This sandboxing option is particularly relevant due to the high amount of recently discovered namespacing related vulnerabilities in the kernel.
systemd-udev's .link files gained support for a new AutoNegotiation= setting for configuring Ethernet auto-negotiation.
systemd-networkd's .network files gained support for a new ListenPort= setting in the [DHCP] section to explicitly configure the UDP client port the DHCP client shall listen on.
.network files gained a new Unmanaged= boolean setting for explicitly excluding one or more interfaces from management by systemd-networkd.
The systemd-networkd ProxyARP= option has been renamed to IPV4ProxyARP=. Similarly, VXLAN-specific option ARPProxy= has been renamed to ReduceARPProxy=. The old names continue to be available for compatibility.
systemd-networkd gained support for configuring IPv6 Proxy NDP addresses via the new IPv6ProxyNDPAddress= .network file setting.
systemd-networkd's bonding device support gained support for two new configuration options ActiveSlave= and PrimarySlave=.
The various options in the [Match] section of .network files gained support for negative matching.
New systemd-specific mount options are now understood in /etc/fstab:
x-systemd.mount-timeout= may be used to configure the maximum permitted runtime of the mount command.
x-systemd.device-bound may be set to bind a mount point to its backing device unit, in order to automatically remove a mount point if its backing device is unplugged. This option may also be configured through the new SYSTEMD_MOUNT_DEVICE_BOUND udev property on the block device, which is now automatically set for all CDROM drives, so that mounted CDs are automatically unmounted when they are removed from the drive.
x-systemd.after= and x-systemd.before= may be used to explicitly order a mount after or before another unit or mount point.
Enqueued start jobs for device units are now automatically garbage collected if there are no jobs waiting for them anymore.
systemctl list-jobs gained two new switches: with --after, for every queued job the jobs it's waiting for are shown; with --before the jobs which it's blocking are shown.
systemd-nspawn gained support for ephemeral boots from disk images (or in other words: --ephemeral and --image= may now be combined). Moreover, ephemeral boots are now supported for normal directories, even if the backing file system is not btrfs. Of course, if the file system does not support file system snapshots or reflinks, the initial copy operation will be relatively expensive, but this should still be suitable for many use cases.
Calendar time specifications in .timer units now support specifications relative to the end of a month by using "~" instead of "-" as separator between month and day. For example, "*-02~03" means "the third last day in February". In addition a new syntax for repeated events has been added using the "/" character. For example, "9..17/2:00" means "every two hours from 9am to 5pm".
systemd-socket-proxyd gained a new parameter --connections-max= for configuring the maximum number of concurrent connections.
sd-id128 gained a new API for generating unique IDs for the host in a way that does not leak the machine ID. Specifically, sd_id128_get_machine_app_specific() derives an ID based on the machine ID a in well-defined, non-reversible, stable way. This is useful whenever an identifier for the host is needed but where the identifier shall not be useful to identify the system beyond the scope of the application itself. (Internally this uses HMAC-SHA256 as keyed hash function using the machine ID as input.)
NotifyAccess= gained a new supported value "exec". When set notifications are accepted from all processes systemd itself invoked, including all control processes.
.nspawn files gained support for defining overlay mounts using the Overlay= and OverlayReadOnly= options. Previously this functionality was only available on the systemd-nspawn command line.
systemd-nspawn's --bind= and --overlay= options gained support for bind/overlay mounts whose source lies within the container tree by prefixing the source path with "+".
systemd-nspawn's --bind= and --overlay= options gained support for automatically allocating a temporary source directory in /var/tmp that is removed when the container dies. Specifically, if the source directory is specified as empty string this mechanism is selected. An example usage is --overlay=+/var::/var, which creates an overlay mount based on the original /var contained in the image, overlayed with a temporary directory in the host's /var/tmp. This way changes to /var are automatically flushed when the container shuts down.
systemd-nspawn --image= option does now permit raw file system block devices (in addition to images containing partition tables, as before).
The disk image dissection logic in systemd-nspawn gained support for automatically setting up LUKS encrypted as well as Verity protected partitions. When a container is booted from an encrypted image the passphrase is queried at start-up time. When a container with Verity data is started, the root hash is search in a ".roothash" file accompanying the disk image (alternatively, pass the root hash via the new --root-hash= command line option).
A new tool /usr/lib/systemd/systemd-dissect has been added that may be used to dissect disk images the same way as systemd-nspawn does it, following the Bootable Partition Specification. It may even be used to mount disk images with complex partition setups (including LUKS and Verity partitions) to a local host directory, in order to inspect them. This tool is not considered public API (yet), and is thus not installed into /usr/bin. Please do not rely on its existence, since it might go away or be changed in later systemd versions.
A new generator "systemd-verity-generator" has been added, similar in style to "systemd-cryptsetup-generator", permitting automatic setup of Verity root partitions when systemd boots up. In order to make use of this your partition setup should follow the Discoverable Partitions Specification, and the GPT partition ID of the root file system partition should be identical to the upper 128bit of the Verity root hash. The GPT partition ID of the Verity partition protecting it should be the lower 128bit of the Verity root hash. If the partition image follows this model it is sufficient to specify a single "roothash=" kernel command line argument to both configure which root image and verity partition to use as well as the root hash for it. Note that systemd-nspawn's Verity support follows the same semantics, meaning that disk images with proper Verity data in place may be booted in containers with systemd-nspawn as well as on physical systems via the verity generator. Also note that the "mkosi" tool available at https://github.com/systemd/mkosi has been updated to generate Verity protected disk images following this scheme. In fact, it has been updated to generate disk images that optionally implement a complete UEFI SecureBoot trust chain, involving a signed kernel and initrd image that incorporates such a root hash as well as a Verity-enabled root partition.
The hardware database (hwdb) udev supports has been updated to carry accelerometer quirks.
All system services are now run with a fresh kernel keyring set up for them. The invocation ID is stored by default in it, thus providing a safe, non-overridable way to determine the invocation ID of each service.
Service unit files gained new BindPaths= and BindReadOnlyPaths= options for bind mounting arbitrary paths in a service-specific way. When these options are used, arbitrary host or service files and directories may be mounted to arbitrary locations in the service's view.
Documentation has been added that lists all of systemd's low-level environment variables:
https://github.com/systemd/systemd/blob/master/ENVIRONMENT.md
sd-daemon gained a new API sd_is_socket_sockaddr() for determining whether a specific socket file descriptor matches a specified socket address.
systemd-firstboot has been updated to check for the systemd.firstboot= kernel command line option. It accepts a boolean and when set to false the first boot questions are skipped.
systemd-fstab-generator has been updated to check for the systemd.volatile= kernel command line option, which either takes an optional boolean parameter or the special value "state". If used the system may be booted in a "volatile" boot mode. Specifically, "systemd.volatile" is used, the root directory will be mounted as tmpfs, and only /usr is mounted from the actual root file system. If "systemd.volatile=state" is used, the root directory will be mounted as usual, but /var is mounted as tmpfs. This concept provides similar functionality as systemd-nspawn's --volatile= option, but provides it on physical boots. Use this option for implementing stateless systems, or testing systems with all state and/or configuration reset to the defaults. (Note though that many distributions are not prepared to boot up without a populated /etc or /var, though.)
systemd-gpt-auto-generator gained support for LUKS encrypted root partitions. Previously it only supported LUKS encrypted partitions for all other uses, except for the root partition itself.
Socket units gained support for listening on AF_VSOCK sockets for communication in virtualized QEMU environments.
The "configure" script gained a new option --with-fallback-hostname= for specifying the fallback hostname to use if none is configured in /etc/hostname. For example, by specifying --with-fallback-hostname=fedora it is possible to default to a hostname of "fedora" on pristine installations.
systemd-cgls gained support for a new --unit= switch for listing only the control groups of a specific unit. Similar --user-unit= has been added for listing only the control groups of a specific user unit.
systemd-mount gained a new --umount switch for unmounting a mount or automount point (and all mount/automount points below it).
systemd will now refuse full configuration reloads (via systemctl daemon-reload and related calls) unless at least 16MiB of free space are available in /run. This is a safety precaution in order to ensure that generators can safely operate after the reload completed.
A new unit file option RootImage= has been added, which has a similar effect as RootDirectory= but mounts the service's root directory from a disk image instead of plain directory. This logic reuses the same image dissection and mount logic that systemd-nspawn already uses, and hence supports any disk images systemd-nspawn supports, including those following the Discoverable Partition Specification, as well as Verity enabled images. This option enables systemd to run system services directly off disk images acting as resource bundles, possibly even including full integrity data.
A new MountAPIVFS= unit file option has been added, taking a boolean argument. If enabled /proc, /sys and /dev (collectively called the "API VFS") will be mounted for the service. This is only relevant if RootDirectory= or RootImage= is used for the service, as these mounts are of course in place in the host mount namespace anyway.
systemd-nspawn gained support for a new --pivot-root= switch. If specified the root directory within the container image is pivoted to the specified mount point, while the original root disk is moved to a different place. This option enables booting of ostree images directly with systemd-nspawn.
The systemd build scripts will no longer complain if the NTP server addresses are not changed from the defaults. Google now supports these NTP servers officially. We still recommend downstreams to properly register an NTP pool with the NTP pool project though.
coredumpctl gained new new "--reverse" option for printing the list of coredumps in reverse order.
coredumpctl will now show additional information about truncated and inaccessible coredumps, as well as coredumps that are still being processed. It also gained a new --quiet switch for suppressing additional informational message in its output.
coredumpctl gained support for only showing coredumps newer and/or older than specific timestamps, using the new --since= and --until= options, reminiscent of journalctl's options by the same name.
The systemd-coredump logic has been improved so that it may be reused to collect backtraces in non-compiled languages, for example in scripting languages such as Python.
machinectl will now show the UID shift of local containers, if user namespacing is enabled for them.
systemd will now optionally run "environment generator" binaries at configuration load time. They may be used to add environment variables to the environment block passed to services invoked. One user environment generator is shipped by default that sets up environment variables based on files dropped into /etc/environment.d and ~/.config/environment.d/.
systemd-resolved now includes the new, recently published 2017 DNSSEC root key (KSK).
hostnamed has been updated to report a new chassis type of "convertible" to cover "foldable" laptops that can both act as a tablet and as a laptop, such as various Lenovo Yoga devices.

New in systemd 232 (Nov 4, 2016)

The new RemoveIPC= option can be used to remove IPC objects owned by the user or group of a service when that service exits.
The new ProtectKernelModules= option can be used to disable explicit load and unload operations of kernel modules by a service. In addition access to /usr/lib/modules is removed if this option is set.
ProtectSystem= option gained a new value "strict", which causes the whole file system tree with the exception of /dev, /proc, and /sys, to be remounted read-only for a service.
The new ProtectKernelTunables= option can be used to disable modification of configuration files in /sys and /proc by a service. Various directories and files are remounted read-only, so access is restricted even if the file permissions would allow it.
The new ProtectControlGroups= option can be used to disable write access by a service to /sys/fs/cgroup.
Various systemd services have been hardened with ProtectKernelTunables=yes, ProtectControlGroups=yes, RestrictAddressFamilies=.
Support for dynamically creating users for the lifetime of a service has been added. If DynamicUser=yes is specified, user and group IDs will be allocated from the range 61184..65519 for the lifetime of the service. They can be resolved using the new nss-systemd.so NSS module. The module must be enabled in /etc/nsswitch.conf. Services started in this way have PrivateTmp= and RemoveIPC= enabled, so that any resources allocated by the service will be cleaned up when the service exits. They also have ProtectHome=read-only and ProtectSystem=strict enabled, so they are not able to make any permanent modifications to the system.
The nss-systemd module also always resolves root and nobody, making it possible to have no /etc/passwd or /etc/group files in minimal container or chroot environments.
Services may be started with their own user namespace using the new boolean PrivateUsers= option. Only root, nobody, and the uid/gid under which the service is running are mapped. All other users are mapped to nobody.
Support for the cgroup namespace has been added to systemd-nspawn. If supported by kernel, the container system started by systemd-nspawn will have its own view of the cgroup hierarchy. This new behaviour can be disabled using $SYSTEMD_NSPAWN_USE_CGNS environment variable.
The new MemorySwapMax= option can be used to limit the maximum swap usage under the unified cgroup hierarchy.
Support for the CPU controller in the unified cgroup hierarchy has been added, via the CPUWeight=, CPUStartupWeight=, CPUAccounting= options. This controller requires out-of-tree patches for the kernel and the support is provisional.
Mount and automount units may now be created transiently (i.e. dynamically at runtime via the bus API, instead of requiring unit files in the file system).
systemd-mount is a new tool which may mount file systems – much like mount(8), optionally pulling in additional dependencies through transient .mount and .automount units. For example, this tool automatically runs fsck on a backing block device before mounting, and allows the automount logic to be used dynamically from the command line for establishing mount points. This tool is particularly useful when dealing with removable media, as it will ensure fsck is run – if necessary – before the first access and that the file system is quickly unmounted after each access by utilizing the automount logic. This maximizes the chance that the file system on the removable media stays in a clean state, and if it isn't in a clean state is fixed automatically.
LazyUnmount=yes option for mount units has been added to expose the umount --lazy option. Similarly, ForceUnmount=yes exposes the --force option.
/efi will be used as the mount point of the EFI boot partition, if the directory is present, and the mount point was not configured through other means (e.g. fstab). If /efi directory does not exist, /boot will be used as before. This makes it easier to automatically mount the EFI partition on systems where /boot is used for something else.
When operating on GPT disk images for containers, systemd-nspawn will now mount the ESP to /boot or /efi according to the same rules as PID 1 running on a host. This allows tools like "bootctl" to operate correctly within such containers, in order to make container images bootable on physical systems.
disk/by-id and disk/by-path symlinks are now created for NVMe drives.
Two new user session targets have been added to support running graphical sessions under the systemd --user instance: graphical-session.target and graphical-session-pre.target. See systemd.special(7) for a description of how those targets should be used.
The vconsole initialization code has been significantly reworked to use KD_FONT_OP_GET/SET ioctls instead of KD_FONT_OP_COPY and better support unicode keymaps. Font and keymap configuration will now be copied to all allocated virtual consoles.
FreeBSD's bhyve virtualization is now detected.
Information recorded in the journal for core dumps now includes the contents of /proc/mountinfo and the command line of the process at the top of the process hierarchy (which is usually the init process of the container).
systemd-journal-gatewayd learned the --directory= option to serve files from the specified location.
journalctl --root=… can be used to peruse the journal in the /var/log/ directories inside of a container tree. This is similar to the existing --machine= option, but does not require the container to be active.
The hardware database has been extended to support ID_INPUT_TRACKBALL, used in addition to ID_INPUT_MOUSE to identify trackball devices. MOUSE_WHEEL_CLICK_ANGLE_HORIZONTAL hwdb property has been added to specify the click rate for mice which include a horizontal wheel with a click rate that is different than the one for the vertical wheel.
systemd-run gained a new --wait option that makes service execution synchronous. (Specifically, the command will not return until the specified service binary exited.)
systemctl gained a new --wait option that causes the start command to wait until the units being started have terminated again.
A new journal output mode "short-full" has been added which displays timestamps with abbreviated English day names and adds a timezone suffix. Those timestamps include more information than the default "short" output mode, and can be passed directly to journalctl's --since= and --until= options.
/etc/resolv.conf will be bind-mounted into containers started by systemd-nspawn, if possible, so any changes to resolv.conf contents are automatically propagated to the container.
The number of instances for socket-activated services originating from a single IP address can be limited with MaxConnectionsPerSource=, extending the existing setting of MaxConnections=.
systemd-networkd gained support for vcan ("Virtual CAN") interface configuration.
.netdev and .network configuration can now be extended through drop-ins.
UDP Segmentation Offload, TCP Segmentation Offload, Generic Segmentation Offload, Generic Receive Offload, Large Receive Offload can be enabled and disabled using the new UDPSegmentationOffload=, TCPSegmentationOffload=, GenericSegmentationOffload=, GenericReceiveOffload=, LargeReceiveOffload= options in the [Link] section of .link files.
The Spanning Tree Protocol, Priority, Aging Time, and the Default Port VLAN ID can be configured for bridge devices using the new STP=, Priority=, AgeingTimeSec=, and DefaultPVID= settings in the [Bridge] section of .netdev files.
The route table to which routes received over DHCP or RA should be added can be configured with the new RouteTable= option in the [DHCP] and [IPv6AcceptRA] sections of .network files.
The Address Resolution Protocol can be disabled on links managed by systemd-networkd using the ARP=no setting in the [Link] section of .network files.
New environment variables $SERVICE_RESULT, $EXIT_CODE and $EXIT_STATUS are set for ExecStop= and ExecStopPost= commands, and encode information about the result and exit codes of the current service runtime cycle.
systemd-sysctl will now configure kernel parameters in the order they occur in the configuration files. This matches what sysctl has been traditionally doing.
kernel-install "plugins" that are executed to perform various tasks after a new kernel is added and before an old one is removed can now return a special value to terminate the procedure and prevent any later plugins from running.
Journald's SplitMode=login setting has been deprecated. It has been removed from documentation, and its use is discouraged. In a future release it will be completely removed, and made equivalent to current default of SplitMode=uid.
Storage=both option setting in /etc/systemd/coredump.conf has been removed. With fast LZ4 compression storing the core dump twice is not useful.
The --share-system systemd-nspawn option has been replaced with an (undocumented) variable $SYSTEMD_NSPAWN_SHARE_SYSTEM, but the use of this functionality is discouraged. In addition the variables $SYSTEMD_NSPAWN_SHARE_NS_IPC, $SYSTEMD_NSPAWN_SHARE_NS_PID, $SYSTEMD_NSPAWN_SHARE_NS_UTS may be used to control the unsharing of individual namespaces.
"machinectl list" now shows the IP address of running containers in the output, as well as OS release information.
"loginctl list" now shows the TTY of each session in the output.
sd-bus gained new API calls sd_bus_track_set_recursive(), sd_bus_track_get_recursive(), sd_bus_track_count_name(), sd_bus_track_count_sender(). They permit usage of sd_bus_track peer tracking objects in a "recursive" mode, where a single client can be counted multiple times, if it takes multiple references.
sd-bus gained new API calls sd_bus_set_exit_on_disconnect() and sd_bus_get_exit_on_disconnect(). They may be used to to make a process using sd-bus automatically exit if the bus connection is severed.
Bus clients of the service manager may now "pin" loaded units into memory, by taking an explicit reference on them. This is useful to ensure the client can retrieve runtime data about the service even after the service completed execution. Taking such a reference is available only for privileged clients and should be helpful to watch running services in a race-free manner, and in particular collect information about exit statuses and results.
The nss-resolve module has been changed to strictly return UNAVAIL when communication via D-Bus with resolved failed, and NOTFOUND when a lookup completed but was negative. This means it is now possible to neatly configure fallbacks using nsswitch.conf result checking expressions. Taking benefit of this, the new recommended configuration line for the "hosts" entry in /etc/nsswitch.conf is: hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname
A new setting CtrlAltDelBurstAction= has been added to /etc/systemd/system.conf which may be used to configure the precise behaviour if the user on the console presses Ctrl-Alt-Del more often than 7 times in 2s. Previously this would unconditionally result in an expedited, immediate reboot. With this new setting the precise operation may be configured in more detail, and also turned off entirely.
In .netdev files two new settings RemoteChecksumTx= and RemoteChecksumRx= are now understood that permit configuring the remote checksumming logic for VXLAN networks.
The service manager learnt a new "invocation ID" concept for invoked services. Each runtime cycle of a service will get a new invocation ID (a 128bit random UUID) assigned that identifies the current run of the service uniquely and globally. A new invocation ID is generated each time a service starts up. The journal will store the invocation ID of a service along with any logged messages, thus making the invocation ID useful for matching the online runtime of a service with the offline log data it generated in a safe way without relying on synchronized timestamps. In many ways this new service invocation ID concept is similar to the kernel's boot ID concept that uniquely and globally identifies the runtime of each boot. The invocation ID of a service is passed to the service itself via an environment variable ($INVOCATION_ID). A new bus call GetUnitByInvocationID() has been added that is similar to GetUnit() but instead of retrieving the bus path for a unit by its name retrieves it by its invocation ID. The returned path is valid only as long as the passed invocation ID is current.
systemd-resolved gained a new "DNSStubListener" setting in resolved.conf. It either takes a boolean value or the special values "udp" and "tcp", and configures whether to enable the stub DNS listener on 127.0.0.53:53.
IP addresses configured via networkd may now carry additional configuration settings supported by the kernel. New options include: HomeAddress=, DuplicateAddressDetection=, ManageTemporaryAddress=, PrefixRoute=, AutoJoin=.
The PAM configuration fragment file for "user at .service" shipped with systemd (i.e. the --user instance of systemd) has been stripped to the minimum necessary to make the system boot. Previously, it contained Fedora-specific stanzas that did not apply to other distributions. It is expected that downstream distributions add additional configuration lines, matching their needs to this file, using it only as rough template of what systemd itself needs. Note that this reduced fragment does not even include an invocation of pam_limits which most distributions probably want to add, even though systemd itself does not need it. (There's also the new build time option --with-pamconfdir=no to disable installation of the PAM fragment entirely.)
If PrivateDevices=yes is set for a service the CAP_SYS_RAWIO capability is now also dropped from its set (in addition to CAP_SYS_MKNOD as before).
In service unit files it is now possible to connect a specific named file descriptor with stdin/stdout/stdout of an executed service. The name may be specified in matching .socket units using the FileDescriptorName= setting.
A number of journal settings may now be configured on the kernel command line. Specifically, the following options are now understood: systemd.journald.max_level_console=, systemd.journald.max_level_store=, systemd.journald.max_level_syslog=, systemd.journald.max_level_kmsg=, systemd.journald.max_level_wall=.
"systemctl is-enabled --full" will now show by which symlinks a unit file is enabled in the unit dependency tree.
Support for VeraCrypt encrypted partitions has been added to the "cryptsetup" logic and /etc/crypttab.
systemd-detect-virt gained support for a new --private-users switch that checks whether the invoking processes are running inside a user namespace. Similar, a new special value "private-users" for the existing ConditionVirtualization= setting has been added, permitting skipping of specific units in user namespace environments.

New in systemd 231 (Jul 25, 2016)

In service units the various ExecXYZ= settings have been extended with an additional special character as first argument of the assigned value: if the character '+' is used the specified command line it will be run with full privileges, regardless of User=, Group=, CapabilityBoundingSet= and similar options. The effect is similar to the existing PermissionsStartOnly= option, but allows configuration of this concept for each executed command line independently.
Services may now alter the service watchdog timeout at runtime by sending a WATCHDOG_USEC= message via sd_notify().
MemoryLimit= and related unit settings now optionally take percentage specifications. The percentage is taken relative to the amount of physical memory in the system (or in case of containers, the assigned amount of memory). This allows scaling service resources neatly with the amount of RAM available on the system. Similarly, systemd-logind's RuntimeDirectorySize= option now also optionally takes percentage values.
In similar fashion TasksMax= takes percentage values now, too. The value is taken relative to the configured maximum number of processes on the system. The per-service task maximum has been changed to 15% using this functionality. (Effectively this is an increase of 512 → 4915 for service units, given the kernel's default pid_max setting.)
Calendar time specifications in .timer units now understand a ".." syntax for time ranges. Example: "4..7:10" may now be used for defining a timer that is triggered at 4:10am, 5:10am, 6:10am and 7:10am every day.
The InaccessableDirectories=, ReadOnlyDirectories= and ReadWriteDirectories= unit file settings have been renamed to InaccessablePaths=, ReadOnlyPaths= and ReadWritePaths= and may now be applied to all kinds of file nodes, and not just directories, with the exception of symlinks. Specifically these settings may now be used on block and character device nodes, UNIX sockets and FIFOS as well as regular files. The old names of these settings remain available for compatibility.
systemd will now log about all service processes it kills forcibly (using SIGKILL) because they remained after the clean shutdown phase of the service completed. This should help identifying services that shut down uncleanly. Moreover if KillUserProcesses= is enabled in systemd-logind's configuration a similar log message is generated for processes killed at the end of each session due to this setting.
systemd will now set the $JOURNAL_STREAM environment variable for all services whose stdout/stderr are connected to the Journal (which effectively means by default: all services). The variable contains the device and inode number of the file descriptor used for stdout/stderr. This may be used by invoked programs to detect whether their stdout/stderr is connected to the Journal, in which case they can switch over to direct Journal communication, thus being able to pass extended, structured metadata along with their log messages. As one example, this is now used by glib's logging primitives.
When using systemd's default tmp.mount unit for /tmp, the mount point will now be established with the "nosuid" and "nodev" options. This avoids privilege escalation attacks that put traps and exploits into /tmp. However, this might cause problems if you e. g. put container images or overlays into /tmp; if you need this, override tmp.mount's "Options=" with a drop-in, or mount /tmp from /etc/fstab with your desired options.
systemd now supports the "memory" cgroup controller also on cgroupsv2.
The systemd-cgtop tool now optionally takes a control group path as command line argument. If specified, the control group list shown is limited to subgroups of that group.
The SystemCallFilter= unit file setting gained support for pre-defined, named system call filter sets. For example SystemCallFilter=@clock is now an effective way to make all clock changing-related system calls unavailable to a service. A number of similar pre-defined groups are defined. Writing system call filters for system services is simplified substantially with this new concept. Accordingly, all of systemd's own, long-running services now enable system call filtering based on this, by default.
A new service setting MemoryDenyWriteExecute= has been added, taking a boolean value. If turned on, a service may no longer create memory mappings that are writable and executable at the same time. This enhances security for services where this is enabled as it becomes harder to dynamically write and then execute memory in exploited service processes. This option has been enabled for all of systemd's own long-running services.
A new RestrictRealtime= service setting has been added, taking a boolean argument. If set the service's processes may no longer acquire realtime scheduling. This improves security as realtime scheduling may otherwise be used to easily freeze the system.
systemd-nspawn gained a new switch --notify-ready= taking a boolean value. This may be used for requesting that the system manager inside of the container reports start-up completion to nspawn which then propagates this notification further to the service manager supervising nspawn itself. A related option NotifyReady= in .nspawn files has been added too. This functionality allows ordering of the start-up of multiple containers using the usual systemd ordering primitives.
machinectl gained a new command "stop" that is an alias for "terminate".
systemd-resolved gained support for contacting DNS servers on link-local IPv6 addresses.
If systemd-resolved receives the SIGUSR2 signal it will now flush all its caches. A method call for requesting the same operation has been added to the bus API too, and is made available via "systemd-resolve --flush-caches".
systemd-resolve gained a new --status switch. If passed a brief summary of the used DNS configuration with per-interface information is shown.
resolved.conf gained a new Cache= boolean option, defaulting to on. If turned off local DNS caching is disabled. This comes with a performance penalty in particular when DNSSEC is enabled. Note that resolved disables its internal caching implicitly anyway, when the configured DNS server is on a host-local IP address such as ::1 or 127.0.0.1, thus automatically avoiding double local caching.
systemd-resolved now listens on the local IP address 127.0.0.53:53 for DNS requests. This improves compatibility with local programs that do not use the libc NSS or systemd-resolved's bus APIs for name resolution. This minimal DNS service is only available to local programs and does not implement the full DNS protocol, but enough to cover local DNS clients. A new, static resolv.conf file, listing just this DNS server is now shipped in /usr/lib/systemd/resolv.conf. It is now recommended to make /etc/resolv.conf a symlink to this file in order to route all DNS lookups to systemd-resolved, regardless if done via NSS, the bus API or raw DNS packets. Note that this local DNS service is not as fully featured as the libc NSS or systemd-resolved's bus APIs. For example, as unicast DNS cannot be used to deliver link-local address information (as this implies sending a local interface index along), LLMNR/mDNS support via this interface is severely restricted. It is thus strongly recommended for all applications to use the libc NSS API or native systemd-resolved bus API instead.
systemd-networkd's bridge support learned a new setting VLANFiltering= for controlling VLAN filtering. Moreover a new section in .network files has been added for configuring VLAN bridging in more detail: VLAN=, EgressUntagged=, PVID= in [BridgeVLAN].
systemd-networkd's IPv6 Router Advertisement code now makes use of the DNSSL and RDNSS options. This means IPv6 DNS configuration may now be acquired without relying on DHCPv6. Two new options UseDomains= and UseDNS= have been added to configure this behaviour.
systemd-networkd's IPv6AcceptRouterAdvertisements= option has been renamed IPv6AcceptRA=, without altering its behaviour. The old setting name remains available for compatibility reasons.
The systemd-networkd VTI/VTI6 tunneling support gained new options Key=, InputKey= and OutputKey=.
systemd-networkd gained support for VRF ("Virtual Routing Function") interface configuration.
"systemctl edit" may now be used to create new unit files by specifying the --force switch.
sd-event gained a new function sd_event_get_iteration() for requesting the current iteration counter of the event loop. It starts at zero and is increased by one with each event loop iteration.
A new rpm macro %systemd_ordering is provided by the macros.systemd file. It can be used in lieu of %systemd_requires in packages which don't use any systemd functionality and are intended to be installed in minimal containers without systemd present. This macro provides ordering dependecies to ensure that if the package is installed in the same rpm transaction as systemd, systemd will be installed before the scriptlets for the package are executed, allowing unit presets to be handled.
New macros %_systemdgeneratordir and %_systemdusergeneratordir have been added to simplify packaging of generators.
The os-release file gained VERSION_CODENAME field for the distribution nickname (e.g. VERSION_CODENAME=woody).
New udev property UDEV_DISABLE_PERSISTENT_STORAGE_RULES_FLAG=1 can be set to disable parsing of metadata and the creation of persistent symlinks for that device.
The v230 change to tag framebuffer devices (/dev/fb*) with "uaccess" to make them available to logged-in users has been reverted.
Much of the common code of the various systemd components is now built into an internal shared library libsystemd-shared-231.so (incorporating the systemd version number in the name, to be updated with future releases) that the components link to. This should decrease systemd footprint both in memory during runtime and on disk. Note that the shared library is not for public use, and is neither API not ABI stable, but is likely to change with every new released update. Packagers need to make sure that binaries linking to libsystemd-shared.so are updated in step with the library.
Configuration for "mkosi" is now part of the systemd repository. mkosi is a tool to easily build legacy-free OS images, and is available on github: https://github.com/systemd/mkosi. If "mkosi" is invoked in the build tree a new raw OS image is generated incorporating the systemd sources currently being worked on and a clean, fresh distribution installation. The generated OS image may be booted up with "systemd-nspawn -b -i", qemu-kvm or on any physcial UEFI PC. This functionality is particularly useful to easily test local changes made to systemd in a pristine, defined environment. See HACKING for details.

New in systemd 230 (May 22, 2016)

DNSSEC is now turned on by default in systemd-resolved (in "allow-downgrade" mode), but may be turned off during compile time by passing "--with-default-dnssec=no" to "configure" (and of course, during runtime with DNSSEC= in resolved.conf). We recommend downstreams to leave this on at least during development cycles and report any issues with the DNSSEC logic upstream. We are very interested in collecting feedback about the DNSSEC validator and its limitations in the wild. Note however, that DNSSEC support is probably nothing downstreams should turn on in stable distros just yet, as it might create incompatibilities with a few DNS servers and networks. We tried hard to make sure we downgrade to non-DNSSEC mode automatically whenever we detect such incompatible setups, but there might be systems we do not cover yet. Hence: please help us testing the DNSSEC code, leave this on where you can, report back, but then again don't consider turning this on in your stable, LTS or production release just yet. (Note that you have to enable nss-resolve in /etc/nsswitch.conf, to actually use systemd-resolved and its DNSSEC mode for host name resolution from local applications.)
systemd-resolve conveniently resolves DANE records with the --tlsa option and OPENPGPKEY records with the --openpgp option. It also supports dumping raw DNS record data via the new --raw= switch.
systemd-logind will now by default terminate user processes that are part of the user session scope unit (session-XX.scope) when the user logs out. This behavior is controlled by the KillUserProcesses= setting in logind.conf, and the previous default of "no" is now changed to "yes". This means that user sessions will be properly cleaned up after, but additional steps are necessary to allow intentionally long-running processes to survive logout.
While the user is logged in at least once, user at .service is running, and any service that should survive the end of any individual login session can be started at a user service or scope using systemd-run. systemd-run(1) man page has been extended with an example which shows how to run screen in a scope unit underneath user at .service. The same command works for tmux.
After the user logs out of all sessions, user at .service will be terminated too, by default, unless the user has "lingering" enabled. To effectively allow users to run long-term tasks even if they are logged out, lingering must be enabled for them. See loginctl(1) for details. The default polkit policy was modified to allow users to set lingering for themselves without authentication.
Previous defaults can be restored at compile time by the --without-kill-user-processes option to "configure".
systemd-logind gained new configuration settings SessionsMax= and InhibitorsMax=, both with a default of 8192. It will not register new user sessions or inhibitors above this limit.
systemd-logind will now reload configuration on SIGHUP.
The unified cgroup hierarchy added in Linux 4.5 is now supported. Use systemd.unified_cgroup_hierarchy=1 on the kernel command line to enable. Also, support for the "io" cgroup controller in the unified hierarchy has been added, so that the "memory", "pids" and "io" are now the controllers that are supported on the unified hierarchy.
WARNING: it is not possible to use previous systemd versions with systemd.unified_cgroup_hierarchy=1 and the new kernel. Therefore it is necessary to also update systemd in the initramfs if using the unified hierarchy. An updated SELinux policy is also required.
LLDP support has been extended, and both passive (receive-only) and active (sender) modes are supported. Passive mode ("routers-only") is enabled by default in systemd-networkd. Active LLDP mode is enabled by default for containers on the internal network. The "networkctl lldp" command may be used to list information gathered. "networkctl status" will also show basic LLDP information on connected peers now.
The IAID and DUID unique identifier sent in DHCP requests may now be configured for the system and each .network file managed by systemd-networkd using the DUIDType=, DUIDRawData=, IAID= options.
systemd-networkd gained support for configuring proxy ARP support for each interface, via the ProxyArp= setting in .network files. It also gained support for configuring the multicast querier feature of bridge devices, via the new MulticastQuerier= setting in .netdev files. Similarly, snooping on the IGMP traffic can be controlled via the new setting MulticastSnooping=.
A new setting PreferredLifetime= has been added for addresses configured in .network file to configure the lifetime intended for an address.
The systemd-networkd DHCP server gained the option EmitRouter=, which defaults to yes, to configure whether the DHCP Option 3 (Router) should be emitted.
The testing tool /usr/lib/systemd/systemd-activate is renamed to systemd-socket-activate and installed into /usr/bin. It is now fully supported.
systemd-journald now uses separate threads to flush changes to disk when closing journal files, thus reducing impact of slow disk I/O on logging performance.
The sd-journal API gained two new calls sd_journal_open_directory_fd() and sd_journal_open_files_fd() which can be used to open journal files using file descriptors instead of file or directory paths. sd_journal_open_container() has been deprecated, sd_journal_open_directory_fd() should be used instead with the flag SD_JOURNAL_OS_ROOT.
journalctl learned a new output mode "-o short-unix" that outputs log lines prefixed by their UNIX time (i.e. seconds since Jan 1st, 1970 UTC). It also gained support for a new --no-hostname setting to suppress the hostname column in the family of "short" output modes.
systemd-ask-password now optionally skips printing of the password to stdout with --no-output which can be useful in scripts.
Framebuffer devices (/dev/fb*) and 3D printers and scanners (devices tagged with ID_MAKER_TOOL) are now tagged with "uaccess" and are available to logged in users.
The DeviceAllow= unit setting now supports specifiers (with "%").
"systemctl show" gained a new --value switch, which allows print a only the contents of a specific unit property, without also printing the property's name. Similar support was added to "show*" verbs of loginctl and machinectl that output "key=value" lists.
A new unit type "generated" was added for files dynamically generated by generator tools. Similarly, a new unit type "transient" is used for unit files created using the runtime API. "systemctl enable" will refuse to operate on such files.
A new command "systemctl revert" has been added that may be used to revert to the vendor version of a unit file, in case local changes have been made by adding drop-ins or overriding the unit file.
"machinectl clean" gained a new verb to automatically remove all or just hidden container images.
systemd-tmpfiles gained support for a new line type "e" for emptying directories, if they exist, without creating them if they don't.
systemd-nspawn gained support for automatically patching the UID/GIDs of the owners and the ACLs of all files and directories in a container tree to match the UID/GID user namespacing range selected for the container invocation. This mode is enabled via the new --private-user-chown switch. It also gained support for automatically choosing a free, previously unused UID/GID range when starting a container, via the new --private-users=pick setting (which implies --private-user-chown). Together, these options for the first time make user namespacing for nspawn containers fully automatic and thus deployable. The systemd-nspaw at .service template unit file has been changed to use this functionality by default.
systemd-nspawn gained a new --network-zone= switch, that allows creating ad-hoc virtual Ethernet links between multiple containers, that only exist as long as at least one container referencing them is running. This allows easy connecting of multiple containers with a common link that implements an Ethernet broadcast domain. Each of these network "zones" may be named relatively freely by the user, and may be referenced by any number of containers, but each container may only reference one of these "zones". On the lower level, this is implemented by an automatically managed bridge network interface for each zone, that is created when the first container referencing its zone is created and removed when the last one referencing its zone terminates.
The default start timeout may now be configured on the kernel command line via systemd.default_timeout_start_sec=. It was already configurable via the DefaultTimeoutStartSec= option in /etc/systemd/system.conf.
Socket units gained a new TriggerLimitIntervalSec= and TriggerLimitBurst= setting to configure a limit on the activation rate of the socket unit.
The LimitNICE= setting now optionally takes normal UNIX nice values in addition to the raw integer limit value. If the specified parameter is prefixed with "+" or "-" and is in the range -20..19 the value is understood as UNIX nice value. If not prefixed like this it is understood as raw RLIMIT_NICE limit.
Note that the effect of the PrivateDevices= unit file setting changed slightly with this release: the per-device /dev file system will be mounted read-only from this version on, and will have "noexec" set. This (minor) change of behavior might cause some (exceptional) legacy software to break, when PrivateDevices=yes is set for its service. Please leave PrivateDevices= off if you run into problems with this.
systemd-bootchart has been split out to a separate repository: https://github.com/systemd/systemd-bootchart
systemd-bus-proxyd has been removed, as kdbus is unlikely to still be merged into the kernel in its current form.
The compatibility libraries libsystemd-daemon.so, libsystemd-journal.so, libsystemd-id128.so, and libsystemd-login.so which have been deprecated since systemd-209 have been removed along with the corresponding pkg-config files. All symbols provided by those libraries are provided by libsystemd.so.
The Capabilities= unit file setting has been removed (it is ignored for backwards compatibility). AmbientCapabilities= and CapabilityBoundingSet= should be used instead.

New in systemd 229 (Feb 11, 2016)

The systemd-resolved DNS resolver service has gained a substantial set of new features, most prominently it may now act as a DNSSEC validating stub resolver. DNSSEC mode is currently turned off by default, but it is expected that this is turned on by default in one of the next releases. For now, we invite everybody to test the DNSSEC logic by setting DNSSEC=allow-downgrade in /etc/systemd/resolved.conf. The service also gained a full set of D-Bus interfaces, including calls to configure DNS and DNSSEC settings per link (for consumption by external network management software). systemd-resolved (and systemd-networkd along with it) now know to distinguish between "search" and "routing" domains. The former are used to qualify single-label names, the latter are purely used for routing lookups within certain domains to specific links. resolved will now also synthesize RRs for all entries from /etc/hosts.
The systemd-resolve tool (which is a client utility for systemd-resolved, and previously experimental) has been improved considerably and is now fully supported and documented. Hence it has moved from /usr/lib/systemd to /usr/bin.
/dev/disk/by-path/ symlink support has been (re-)added for virtio devices.
The coredump collection logic has been reworked: when a coredump is collected it is now written to disk, compressed and processed (including stacktrace extraction) from a new instantiated service systemd-coredump at .service, instead of directly from the /proc/sys/kernel/core_pattern hook we provide. This is beneficial as processing large coredumps can take up a substantial amount of resources and time, and this previously happened entirely outside of systemd's service supervision. With the new logic the core_pattern hook only does minimal metadata collection before passing off control to the new instantiated service, which is configured with a time limit, a nice level and other settings to minimize negative impact on the rest of the system. Also note that the new logic will honour the RLIMIT_CORE setting of the crashed process, which now allows users and processes to turn off coredumping for their processes by setting this limit.
The RLIMIT_CORE resource limit now defaults to "unlimited" for PID 1 and all forked processes by default. Previously, PID 1 would leave the setting at "0" for all processes, as set by the kernel. Note that the resource limit traditionally has no effect on the generated coredumps on the system if the /proc/sys/kernel/core_pattern hook logic is used. Since the limit is now honoured (see above) its default has been changed so that the coredumping logic is enabled by default for all processes, while allowing specific opt-out.
When the stacktrace is extracted from processes of system users, this is now done as "systemd-coredump" user, in order to sandbox this potentially security sensitive parsing operation. (Note that when processing coredumps of normal users this is done under the user ID of process that crashed, as before.) Packagers should take notice that it is now necessary to create the "systemd-coredump" system user and group at package installation time.
The systemd-activate socket activation testing tool gained support for SOCK_DGRAM and SOCK_SEQPACKET sockets using the new --datagram and --seqpacket switches. It also has been extended to support both new-style and inetd-style file descriptor passing. Use the new --inetd switch to request inetd-style file descriptor passing.
Most systemd tools now honor a new $SYSTEMD_COLORS environment variable, which takes a boolean value. If set to false, ANSI color output is disabled in the tools even when run on a terminal that supports it.
The VXLAN support in networkd now supports two new settings DestinationPort= and PortRange=.
A new systemd.machine_id= kernel command line switch has been added, that may be used to set the machine ID in /etc/machine-id if it is not initialized yet. This command line option has no effect if the file is already initialized.
systemd-nspawn gained a new --as-pid2 switch that invokes any specified command line as PID 2 rather than PID 1 in the container. In this mode PID 1 will be a minimal stub init process that implements the special POSIX and Linux semantics of PID 1 regarding signal and child process management. Note that this stub init process is implemented in nspawn itself and requires no support from the container image. This new logic is useful to support running arbitrary command lines in the container, as normal processes are generally not prepared to run as PID 1.
systemd-nspawn gained a new --chdir= switch for setting the current working directory for the process started in the container.
"journalctl /dev/sda" will now output all kernel log messages from the specified device, in addition to all devices that are parents of it. This should make log output about devices pretty useful, as long as kernel drivers attach enough metadata to the log messages. (The usual SATA drivers do.)
The sd-journal API gained two new calls sd_journal_has_runtime_files() and sd_journal_has_persistent_files() that report whether log data from /run or /var has been found.
journalctl gained a new switch "--fields" that prints all journal record field names currently in use in the journal. This is backed by two new sd-journal API calls sd_journal_enumerate_fields() and sd_journal_restart_fields().
Most configurable timeouts in systemd now expect an argument of "infinity" to turn them off, instead of "0" as before. The semantics from now on is that a timeout of "0" means "now", and "infinity" means "never". To maintain backwards compatibility, "0" continues to turn off previously existing timeout settings.
"systemctl reload-or-try-restart" has been renamed to "systemctl try-reload-or-restart" to clarify what it actually does: the "try" logic applies to both reloading and restarting, not just restarting. The old name continues to be accepted for compatibility.
On boot-up, when PID 1 detects that the system clock is behind the release date of the systemd version in use, the clock is now set to the latter. Previously, this was already done in timesyncd, in order to avoid running with clocks set to the various clock epochs such as 1902, 1938 or 1970. With this change the logic is now done in PID 1 in addition to timesyncd during early boot-up, so that it is enforced before the first process is spawned by systemd. Note that the logic in timesyncd remains, as it is more comprehensive and ensures montonic clocks by maintaining a persistant timestamp file in /var. Since /var is generally not available in earliest boot or the initrd, this part of the logic remains in timesyncd, and is not done by PID 1.
Support for tweaking details in net_cls.class_id through the NetClass= configuration directive has been removed, as the kernel people have decided to deprecate that controller in cgroup v2. Userspace tools such as nftables are moving over to setting rules that are specific to the full cgroup path of a task, which obsoletes these controllers anyway. The NetClass= directive is kept around for legacy compatibility reasons. For a more in-depth description of the kernel change, please refer to the respective upstream commit: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd1060a1d671
A new service setting RuntimeMaxSec= has been added that may be used to specify a maximum runtime for a service. If the timeout is hit, the service is terminated and put into a failure state.
A new service setting AmbientCapabilities= has been added. It allows configuration of additional Linux process capabilities that are passed to the activated processes. This is only available on very recent kernels.
The process resource limit settings in service units may now be used to configure hard and soft limits individually.
The various libsystemd APIs such as sd-bus or sd-event now publicly expose support for gcc's __attribute__((cleanup())) C extension. Specifically, for many object destructor functions alternative versions whose names are suffixed with "p" have been added, which take a pointer to a pointer to the object to destroy, instead of just a pointer to the object itself. This is useful because these destructor functions may be used directly as parameters to the cleanup construct. Internally, systemd has been a heavy user of the GCC extension since a long time, and with this change similar support is now available to consumers of the library outside of systemd. Note that by using this extension in your sources compatibility with old and strictly ANSI compatible C compilers is lost. However, any gcc or LLVM version of recent years have supported this extension.
Timer units gained support for a new setting RandomizedDelaySec= that allows configuring some additional randomized delay to the configured time. This is useful to spread out timer events to avoid load peaks in clusters or larger setups.
Calendar time specifications now support sub-second accuracy.
Socket units now support listening on SCTP and UDP-lite protocol sockets.
The sd-event API now comes with a full set of man pages.
Older versions of systemd contained experimental support for compressing journal files and coredumps with the LZ4 compressor that was not compatible with the lz4 binary (due to API limitations of the lz4 library). This support has been removed; only support for files compatible with the lz4 binary remains. This LZ4 logic is now officially supported and no longer considered experimental.
The dkr image import logic has been removed again from importd. dkr's micro-services focus doesn't fit into the machine image focus of importd, and quickly got out of date with the upstream dkr API.
Creation of the /run/lock/lockdev/ directory was dropped from tmpfiles.d/legacy.conf. Better locking mechanisms like flock() have been available for many years. If you still need this, you need to create your own tmpfiles.d config file with: d /run/lock/lockdev 0775 root lock -

New in systemd 228 (Nov 18, 2015)

A number of properties previously only settable in unit files are now also available as properties to set when creating transient units programmatically via the bus, as it is exposed with systemd-run's --property= setting. Specifically, these are: SyslogIdentifier=, SyslogLevelPrefix=, TimerSlackNSec=, OOMScoreAdjust=, EnvironmentFile=, ReadWriteDirectories=, ReadOnlyDirectories=, InaccessibleDirectories=, ProtectSystem=, ProtectHome=, RuntimeDirectory=.
When creating transient services via the bus API it is now possible to pass in a set of file descriptors to use as STDIN/STDOUT/STDERR for the invoked process.
Slice units may now be created transiently via the bus APIs, similar to the way service and scope units may already be created transiently.
Wherever systemd expects a calendar timestamp specification (like in journalctl's --since= and --until= switches) UTC timestamps are now supported. Timestamps suffixed with "UTC" are now considered to be in Universal Time Coordinated instead of the local timezone. Also, timestamps may now optionally be specified with sub-second accuracy. Both of these additions also apply to recurring calendar event specification, such as OnCalendar= in timer units.
journalctl gained a new "--sync" switch that asks the journal daemon to write all so far unwritten log messages to disk and sync the files, before returning.
systemd-tmpfiles learned two new line types "q" and "Q" that operate like "v", but also set up a basic btrfs quota hierarchy when used on a btrfs file system with quota enabled.
tmpfiles' "v", "q" and "Q" will now create a plain directory instead of a subvolume (even on a btrfs file system) if the root directory is a plain directory, and not a subvolume. This should simplify things with certain chroot() environments which are not aware of the concept of btrfs subvolumes.
systemd-detect-virt gained a new --chroot switch to detect whether execution takes place in a chroot() environment.
CPUAffinity= now takes CPU index ranges in addition to individual indexes.
The various memory-related resource limit settings (such as LimitAS=) now understand the usual K, M, G, ... suffixes to the base of 1024 (IEC). Similar, the time-related resource limit settings understand the usual min, h, day, ... suffixes now.
There's a new system.conf setting DefaultTasksMax= to control the default TasksMax= setting for services and scopes running on the system. (TasksMax= is the primary setting that exposes the "pids" cgroup controller on systemd and was introduced in the previous systemd release.) The setting now defaults to 512, which means services that are not explicitly configured otherwise will only be able to create 512 processes or threads at maximum, from this version on. Note that this means that thread- or process-heavy services might need to be reconfigured to set TasksMax= to a higher value. It is sufficient to set TasksMax= in these specific unit files to a higher value, or even "infinity". Similar, there's now a logind.conf setting UserTasksMax= that defaults to 4096 and limits the total number of processes or tasks each user may own concurrently. nspawn containers also have the TasksMax= value set by default now, to 8192. Note that all of this only has an effect if the "pids" cgroup controller is enabled in the kernel. The general benefit of these changes should be a more robust and safer system, that provides a certain amount of per-service fork() bomb protection.
systemd-nspawn gained the new --network-veth-extra= switch to define additional and arbitrarily-named virtual Ethernet links between the host and the container.
A new service execution setting PassEnvironment= has been added that allows importing select environment variables from PID1's environment block into the environment block of the service.
systemd will now bump the net.unix.max_dgram_qlen to 512 by default now (the kernel default is 16). This is beneficial for avoiding blocking on AF_UNIX/SOCK_DGRAM sockets since it allows substantially larger numbers of queued datagrams. This should increase the capability of systemd to parallelize boot-up, as logging and sd_notify() are unlikely to stall execution anymore. If you need to change the value from the new defaults, use the usual sysctl.d/ snippets.
The compression framing format used by the journal or coredump processing has changed to be in line with what the official LZ4 tools generate. LZ4 compression support in systemd was considered unsupported previously, as the format was not compatible with the normal tools. With this release this has changed now, and it is hence safe for downstream distributions to turn it on. While not compressing as well as the XZ, LZ4 is substantially faster, which makes it a good default choice for the compression logic in the journal and in coredump handling.
Any reference to /etc/mtab has been dropped from systemd. The file has been obsolete since a while, but systemd refused to work on systems where it was incorrectly set up (it should be a symlink or non-existent). Please make sure to update to util-linux 2.27.1 or newer in conjunction with this systemd release, which also drops any reference to /etc/mtab. If you maintain a distribution make sure that no software you package still references it, as this is a likely source of bugs. There's also a glibc bug pending, asking for removal of any reference to this obsolete file: https://sourceware.org/bugzilla/show_bug.cgi?id=19108
Support for the ".snapshot" unit type has been removed. This feature turned out to be little useful and little used, and has now been removed from the core and from systemctl.
The dependency types RequiresOverridable= and RequisiteOverridable= have been removed from systemd. They have been used only very sparingly to our knowledge and other options that provide a similar effect (such as systemctl --mode=ignore-dependencies) are much more useful and commonly used. Moreover, they were only half-way implemented as the option to control behaviour regarding these dependencies was never added to systemctl. By removing these dependency types the execution engine becomes a bit simpler. Unit files that use these dependencies should be changed to use the non-Overridable dependency types instead. In fact, when parsing unit files with these options, that's what systemd will automatically convert them too, but it will also warn, asking users to fix the unit files accordingly. Removal of these dependency types should only affect a negligible number of unit files in the wild.
Behaviour of networkd's IPForward= option changed (again). It will no longer maintain a per-interface setting, but propagate one way from interfaces where this is enabled to the global kernel setting. The global setting will be enabled when requested by a network that is set up, but never be disabled again. This change was made to make sure IPv4 and IPv6 behaviour regarding packet forwarding is similar (as the Linux IPv6 stack does not support per-interface control of this setting) and to minimize surprises.
In unit files the behaviour of %u, %U, %h, %s has changed. These specifiers will now unconditionally resolve to the various user database fields of the user that the systemd instance is running as, instead of the user configured in the specific unit via User=. Note that this effectively doesn't change much, as resolving of these specifiers was already turned off in the --system instance of systemd, as we cannot do NSS lookups from PID 1. In the --user instance of systemd these specifiers where correctly resolved, but hardly made any sense, since the user instance lacks privileges to do user switches anyway, and User= is hence useless. Morever, even in the --user instance of systemd behaviour was awkward as it would only take settings from User= assignment placed before the specifier into account. In order to unify and simplify the logic around this the specifiers will now always resolve to the credentials of the user invoking the manager (which in case of PID 1 is the root user).

New in systemd 227 (Oct 8, 2015)

systemd now depends on util-linux v2.27. More specifically, the newly added mount monitor feature in libmount now replaces systemd's former own implementation.
libmount mandates /etc/mtab not to be regular file, and systemd now enforces this condition at early boot. /etc/mtab has been deprecated and warned about for a very long time, so systems running systemd should already have stopped having this file around as anything else than a symlink to /proc/self/mounts.
Support for the "pids" cgroup controller has been added. It allows accounting the number of tasks in a cgroup and enforcing limits on it. This adds two new setting TasksAccounting= and TasksMax= to each unit, as well as a global option DefaultTasksAccounting=.
Support for the "net_cls" cgroup controller has been added. It allows assigning a net class ID to each task in the cgroup, which can then be used in firewall rules and traffic shaping configurations. Note that the kernel netfilter net class code does not currently work reliably for ingress packets on unestablished sockets.
This adds a new config directive called NetClass= to CGroup enabled units. Allowed values are positive numbers for fixed assignments and "auto" for picking a free value automatically.
'systemctl is-system-running' now returns 'offline' if the system is not booted with systemd. This command can now be used as a substitute for 'systemd-notify --booted'.
Watchdog timeouts have been increased to 3 minutes for all in-tree service files. Apparently, disk IO issues are more frequent than we hoped, and user reported >1 minute waiting for disk IO.
'machine-id-commit' functionality has been merged into 'machine-id-setup --commit'. The separate binary has been removed.
The WorkingDirectory= directive in unit files may now be set to the special value '~'. In this case, the working directory is set to the home directory of the user configured in User=.
"machinectl shell" will now open the shell in the home directory of the selected user by default.
The CrashChVT= configuration file setting is renamed to CrashChangeVT=, following our usual logic of not abbreviating unnecessarily. The old directive is still supported for compat reasons. Also, this directive now takes an integer value between 1 and 63, or a boolean value. The formerly supported '-1' value for disabling stays around for compat reasons.
The PrivateTmp=, PrivateDevices=, PrivateNetwork=, NoNewPrivileges=, TTYPath=, WorkingDirectory= and RootDirectory= properties can now be set for transient units.
The systemd-analyze tool gained a new "set-log-target" verb to change the logging target the system manager logs to dynamically during runtime. This is similar to how "systemd-analyze set-log-level" already changes the log level.
In nspawn /sys is now mounted as tmpfs, with only a selected set of subdirectories mounted in from the real sysfs. This enhances security slightly, and is useful for ensuring user namespaces work correctly.
Support for USB FunctionFS activation has been added. This allows implementation of USB gadget services that are activated as soon as they are requested, so that they don't have to run continously, similar to classic socket activation.
The "systemctl exit" command now optionally takes an additional parameter that sets the exit code to return from the systemd manager when exiting. This is only relevant when running the systemd user instance, or when running the system instance in a container.
sd-bus gained the new API calls sd_bus_path_encode_many() and sd_bus_path_decode_many() that allow easy encoding and decoding of multiple identifier strings inside a D-Bus object path. Another new call sd_bus_default_flush_close() has been added to flush and close per-thread default connections.
systemd-cgtop gained support for a -M/--machine= switch to show the control groups within a certain container only.
"systemctl kill" gained support for an optional --fail switch. If specified the requested operation will fail of no processes have been killed, because the unit had no processes attached, or similar.
A new systemd.crash_reboot=1 kernel command line option has been added that triggers a reboot after crashing. This can also be set through CrashReboot= in systemd.conf.
The RuntimeDirectory= setting now understands unit specifiers like %i or %f.
A new (still internal) libary API sd-ipv4acd has been added, that implements address conflict detection for IPv4. It's based on code from sd-ipv4ll, and will be useful for detecting DHCP address conflicts.
File descriptors passed during socket activation may now be named. A new API sd_listen_fds_with_names() is added to access the names. The default names may be overriden, either in the .socket file using the FileDescriptorName= parameter, or by passing FDNAME= when storing the file descriptors using sd_notify().
systemd-networkd gained support for:
Setting the IPv6 Router Advertisment settings via IPv6AcceptRouterAdvertisements= in .network files.
Configuring the HelloTimeSec=, MaxAgeSec= and ForwardDelaySec= bridge parameters in .netdev files.
Configuring PreferredSource= for static routes in .network files.
The "ask-password" framework used to query for LUKS harddisk passwords or SSL passwords during boot gained support for caching passwords in the kernel keyring, if it is available. This makes sure that the user only has to type in a passphrase once if there are multiple objects to unlock with the same one. Previously, such password caching was available only when Plymouth was used; this moves the caching logic into the systemd codebase itself. The "systemd-ask-password" utility gained a new --keyname= switch to control which kernel keyring key to use for caching a password in. This functionality is also useful for enabling display managers such as gdm to automatically unlock the user's GNOME keyring if its passphrase, the user's password and the harddisk password are the same, if gdm-autologin is used.
When downloading tar or raw images using "machinectl pull-tar" or "machinectl pull-raw", a matching ".nspawn" file is now also downloaded, if it is available and stored next to the image file.
Units of type ".socket" gained a new boolean setting Writable= which is only useful in conjunction with ListenSpecial=. If true, enables opening the specified special file in O_RDWR mode rather than O_RDONLY mode.
systemd-rfkill has been reworked to become a singleton service that is activated through /dev/rfkill on each rfkill state change and saves the settings to disk. This way, systemd-rfkill is now compatible with devices that exist only intermittendly, and even restores state if the previous system shutdown was abrupt rather than clean.
The journal daemon gained support for vacuuming old journal files controlled by the number of files that shall remain, in addition to the already existing control by size and by date. This is useful as journal interleaving performance degrades with too many seperate journal files, and allows putting an effective limit on them. The new setting defaults to 100, but this may be changed by setting SystemMaxFiles= and RuntimeMaxFiles= in journald.conf. Also, the "journalctl" tool gained the new --vacuum-files= switch to manually vacuum journal files to leave only the specified number of files in place.
udev will now create /dev/disk/by-path links for ATA devices on kernels where that is supported.
Galician, Serbian, Turkish and Korean translations were added.

New in systemd 226 (Sep 9, 2015)

The DHCP implementation of systemd-networkd gained a set of new features:
The DHCP server now supports emitting DNS and NTP information. It may be enabled and configured via EmitDNS=, DNS=, EmitNTP=, and NTP=. If transmission of DNS and NTP information is enabled, but no servers are configured, the corresponding uplink information (if there is any) is propagated.
Server and client now support transmission and reception of timezone information. It can be configured via the newly introduced network options UseTimezone=, EmitTimezone=, and Timezone=. Transmission of timezone information is enabled between host and containers by default now: the container will change its local timezone to what the host has set.
Lease timeouts can now be configured via MaxLeaseTimeSec= and DefaultLeaseTimeSec=.
The DHCP server improved on the stability of leases. Clients are more likely to get the same lease information back, even if the server loses state.
The DHCP server supports two new configuration options to control the lease address pool metrics, PoolOffset= and PoolSize=.
The encapsulation limit of tunnels in systemd-networkd may now be configured via 'EncapsulationLimit='. It allows modifying the maximum additional levels of encapsulation that are permitted to be prepended to a packet.
systemd now supports the concept of user buses replacing session buses, if used with dbus-1.10 (and enabled via dbus --enable-user-session). It previously only supported this on kdbus-enabled systems, and this release expands this to 'dbus-daemon' systems.
systemd-networkd now supports predictable interface names for virtio devices.
systemd now optionally supports the new Linux kernel "unified" control group hierarchy. If enabled via the kernel command-line option 'systemd.unified_cgroup_hierarchy=1', systemd will try to mount the unified cgroup hierarchy directly on /sys/fs/cgroup. If not enabled, or not available, systemd will fall back to the legacy cgroup hierarchy setup, as before. Host system and containers can mix and match legacy and unified hierarchies as they wish. nspawn understands the $UNIFIED_CROUP_HIERARCHY environment variable to individually select the hierarchy to use for executed containers. By default, nspawn will use the unified hierarchy for the containers if the host uses the unified hierarchy, and the legacy hierarchy otherwise. Please note that at this point the unified hierarchy is an experimental kernel feature and is likely to change in one of the next kernel releases. Therefore, it should not be enabled by default in downstream distributions yet. The minimum required kernel version for the unified hierarchy to work is 4.2. Note that when the unified hierarchy is used for the first time delegated access to controllers is safe. Because of this systemd-nspawn containers will get access to controllers now, as will systemd user sessions. This means containers and user sessions may now manage their own resources, partitioning up what the system grants them.
A new special scope unit "init.scope" has been introduced that encapsulates PID 1 of the system. It may be used to determine resource usage and enforce resource limits on PID 1 itself. PID 1 hence moved out of the root of the control group tree.
The cgtop tool gained support for filtering out kernel threads when counting tasks in a control group. Also, the count of processes is now recursively summed up by default. Two options -k and --recursive= have been added to revert to old behaviour. The tool has also been updated to work correctly in containers now.
systemd-nspawn's --bind= and --bind-ro= options have been extended to allow creation of non-recursive bind mounts.
libsystemd gained two new calls sd_pid_get_cgroup() and sd_peer_get_cgroup() which return the control group path of a process or peer of a connected AF_UNIX socket. This function call is particularly useful when implementing delegated subtrees support in the control group hierarchy.
The "sd-event" event loop API of libsystemd now supports correct dequeuing of real-time signals, without losing signal events.
When systemd requests a PolicyKit decision when managing units it will now add additional fields to the request, including unit name and desired operation. This enables more powerful PolicyKit policies, that make decisions depending on these parameters.
nspawn learnt support for .nspawn settings files, that may accompany the image files or directories of containers, and may contain additional settings for the container. This is an alternative to configuring container parameters via the nspawn command line.

New in systemd 225 (Aug 29, 2015)

New in systemd 224 (Aug 5, 2015)

New in systemd 223 (Jul 29, 2015)

The python-systemd code has been removed from the systemd repository. A new repository has been created which accommodates the code from now on, and we kindly ask distributions to create a separate package for this: https://github.com/systemd/python-systemd
The systemd daemon will now reload its main configuration (/etc/systemd/system.conf) on daemon-reload.
sd-dhcp now exposes vendor specific extensions via sd_dhcp_lease_get_vendor_specific().
systemd-networkd gained a number of new configuration options.
A new boolean configuration option for TAP devices called 'VNetHeader='. If set, the IFF_VNET_HDR flag is set for the device, thus allowing to send and receive GSO packets.
A new tunnel configuration option called 'CopyDSCP='. If enabled, the DSCP field of ip6 tunnels is copied into the decapsulated packet.
A set of boolean bridge configuration options were added. 'UseBPDU=', 'HairPin=', 'FastLeave=', 'AllowPortToBeRoot=', and 'UnicastFlood=' are now parsed by networkd and applied to the respective bridge link device via the respective IFLA_BRPORT_* netlink attribute.
A new string configuration option to override the hostname sent to a DHCP server, called 'Hostname='. If set and 'SendHostname=' is true, networkd will use the configured hostname instead of the system hostname when sending DHCP requests.
A new tunnel configuration option called 'IPv6FlowLabel='. If set, networkd will configure the IPv6 flow-label of the tunnel device according to RFC2460.
The 'macvtap' virtual network devices are now supported, similar to the already supported 'macvlan' devices.
systemd-resolved now implements RFC5452 to improve resilience against cache poisoning. Additionally, source port randomization is enabled by default to further protect against DNS spoofing attacks.
nss-mymachines now supports translating UIDs and GIDs of running containers with user-namespaces enabled. If a container 'foo' translates a host uid 'UID' to the container uid 'TUID', then nss-mymachines will also map uid 'UID' to/from username 'vu-foo-TUID' (with 'foo' and 'TUID' replaced accordingly). Similarly, groups are mapped as 'vg-foo-TGID'.

New in systemd 221 (Jun 20, 2015)

The sd-bus.h and sd-event.h APIs have now been declared stable and have been added to the official interface of libsystemd.so. sd-bus implements an alternative D-Bus client library, that is relatively easy to use, very efficient and supports both classic D-Bus as well as kdbus as transport backend. sd-event is a generic event loop abstraction that is built around Linux epoll, but adds features such as event prioritization or efficient timer handling. Both APIs are good choices for C programs looking for a bus and/or event loop implementation that is minimal and does not have to be portable to other kernels.
kdbus support is no longer compile-time optional. It is now always built-in. However, it can still be disabled at runtime using the kdbus=0 kernel command line setting, and that setting may be changed to default to off, by specifying --disable-kdbus at build-time. Note though that the kernel command line setting has no effect if the kdbus.ko kernel module is not installed, in which case kdbus is (obviously) also disabled. We encourage all downstream distributions to begin testing kdbus by adding it to the kernel images in the development distributions, and leaving kdbus support in systemd enabled.
The minimal required util-linux version has been bumped to 2.26.
Support for chkconfig (--enable-chkconfig) was removed in favor of calling an abstraction tool /lib/systemd/systemd-sysv-install. This needs to be implemented for your distribution. See "SYSV INIT.D SCRIPTS" in README for details.
If there's a systemd unit and a SysV init script for the same service name, and the user executes "systemctl enable" for it (or a related call), then this will now enable both (or execute the related operation on both), not just the unit.
The libudev API documentation has been converted from gtkdoc into man pages.
gudev has been removed from the systemd tree, it is now an external project.
The systemd-cgtop tool learnt a new --raw switch to generate "raw" (machine parsable) output.
networkd's IPForwarding= .network file setting learnt the new setting "kernel", which ensures that networkd does not change the IP forwarding sysctl from the default kernel state.
The systemd-logind bus API now exposes a new boolean property "Docked" that reports whether logind considers the system "docked", i.e. connected to a docking station or not.

New in systemd 220 (May 22, 2015)

CHANGES WITH 220:
The gudev library has been extracted into a separate repository available at: https://git.gnome.org/browse/libgudev/ It is now managed as part of the Gnome project. Distributions are recommended to pass --disable-gudev to systemd and use gudev from the Gnome project instead. gudev is still included in systemd, for now. It will be removed soon, though. Please also see the announcement-thread on systemd-devel: http://lists.freedesktop.org/archives/systemd-devel/2015-May/032070.html
systemd now exposes a CPUUsageNSec= property for each service unit on the bus, that contains the overall consumed CPU time of a service (the sum of what each process of the service consumed). This value is only available if CPUAccounting= is turned on for a service, and is then shown in the "systemctl status" output.
Support for configuring alternative mappings of the old SysV runlevels to systemd targets has been removed. They are now hardcoded in a way that runlevels 2, 3, 4 all map to multi-user.target and 5 to graphical.target (which previously was already the default behaviour).
The auto-mounter logic gained support for mount point expiry, using a new TimeoutIdleSec= setting in .automount units. (Also available as x-systemd.idle-timeout= in /etc/fstab).
The EFI System Partition (ESP) as mounted to /boot by systemd-efi-boot-generator will now be unmounted automatically after 2 minutes of not being used. This should minimize the risk of ESP corruptions.
New /etc/fstab options x-systemd.requires= and x-systemd.requires-mounts-for= are now supported to express additional dependencies for mounts. This is useful for journalling file systems that support external journal devices or overlay file systems that require underlying file systems to be mounted.
systemd does not support direct live-upgrades (via systemctl daemon-reexec) from versions older than v44 anymore. As no distribution we are aware of shipped such old versions in a stable release this should not be problematic.
When systemd forks off a new per-connection service instance it will now set the $REMOTE_ADDR environment variable to the remote IP address, and $REMOTE_PORT environment variable to the remote IP port. This behaviour is similar to the corresponding environment variables defined by CGI.
systemd-networkd gained support for uplink failure detection. The BindCarrier= option allows binding interface configuration dynamically to the link sense of other interfaces. This is useful to achieve behaviour like in network switches.
systemd-networkd gained support for configuring the DHCP client identifier to use when requesting leases.
systemd-networkd now has a per-network UseNTP= option to configure whether NTP server information acquired via DHCP is passed on to services like systemd-timesyncd.
systemd-networkd gained support for vti6 tunnels.
Note that systemd-networkd manages the sysctl variable /proc/sys/net/ipv[46]/conf/*/forwarding for each interface it is configured for since v219. The variable controls IP forwarding, and is a per-interface alternative to the global /proc/sys/net/ipv[46]/ip_forward. This setting is configurable in the IPForward= option, which defaults to "no". This means if networkd is used for an interface it is no longer sufficient to set the global sysctl option to turn on IP forwarding! Instead, the .network file option IPForward= needs to be turned on! Note that the implementation of this behaviour was broken in v219 and has been fixed in v220.
Many bonding and vxlan options are now configurable in systemd-networkd.
systemd-nspawn gained a new --property= setting to set unit properties for the container scope. This is useful for setting resource parameters (e.g "CPUShares=500") on containers started from the command line.
systemd-nspawn gained a new --private-users= switch to make use of user namespacing available on recent Linux kernels.
systemd-nspawn may now be called as part of a shell pipeline in which case the pipes used for stdin and stdout are passed directly to the process invoked in the container, without indirection via a pseudo tty.
systemd-nspawn gained a new switch to control the UNIX signal to use when killing the init process of the container when shutting down.
systemd-nspawn gained a new --overlay= switch for mounting overlay file systems into the container using the new kernel overlayfs support.
When a container image is imported via systemd-importd and the host file system is not btrfs, a loopback block device file is created in /var/lib/machines.raw with a btrfs file system inside. It is then mounted to /var/lib/machines to enable btrfs features for container management. The loopback file and btrfs file system is grown as needed when container images are imported via systemd-importd.
systemd-machined/systemd-importd gained support for btrfs quota, to enforce container disk space limits on disk. This is exposed in "machinectl set-limit".
systemd-importd now can import containers from local .tar, .raw and .qcow2 images, and export them to .tar and .raw. It can also import dkr v2 images now from the network (on top of v1 as before).
systemd-importd gained support for verifying downloaded images with gpg2 (previously only gpg1 was supported).
systemd-machined, systemd-logind, systemd: most bus calls are now accessible to unprivileged processes via PolicyKit. Also, systemd-logind will now allow users to kill their own sessions without further privileges or authorization.
systemd-shutdownd has been removed. This service was previously responsible for implementing scheduled shutdowns as exposed in /usr/bin/shutdown's time parameter. This functionality has now been moved into systemd-logind and is accessible via a bus interface.
"systemctl reboot" gained a new switch --firmware-setup that can be used to reboot into the EFI firmware setup, if that is available. systemd-logind now exposes an API on the bus to trigger such reboots, in case graphical desktop UIs want to cover this functionality.
"systemctl enable", "systemctl disable" and "systemctl mask" now support a new "--now" switch. If specified the units that are enabled will also be started, and the ones disabled/masked also stopped.
The Gummiboot EFI boot loader tool has been merged into systemd, and renamed to "systemd-boot". The bootctl tool has been updated to support systemd-boot.
An EFI kernel stub has been added that may be used to create kernel EFI binaries that contain not only the actual kernel, but also an initrd, boot splash, command line and OS release information. This combined binary can then be signed as a single image, so that the firmware can verify it all in one step. systemd-boot has special support for EFI binaries created like this and can extract OS release information from them and show them in the boot menu. This functionality is useful to implement cryptographically verified boot schemes.
Optional support has been added to systemd-fsck to pass fsck's progress report to an AF_UNIX socket in the file system.
udev will no longer create device symlinks for all block devices by default. A blacklist for excluding special block devices from this logic has been turned into a whitelist that requires picking block devices explicitly that require device symlinks.
A new (currently still internal) API sd-device.h has been added to libsystemd. This modernized API is supposed to replace libudev eventually. In fact, already much of libudev is now just a wrapper around sd-device.h.
A new hwdb database for storing metadata about pointing stick devices has been added.
systemd-tmpfiles gained support for setting file attributes similar to the "chattr" tool with new 'h' and 'H' lines.
systemd-journald will no longer unconditionally set the btrfs NOCOW flag on new journal files. This is instead done with tmpfiles snippet using the new 'h' line type. This allows easy disabling of this logic, by masking the journal-nocow.conf tmpfiles file.
systemd-journald will now translate audit message types to human readable identifiers when writing them to the journal. This should improve readability of audit messages.
The LUKS logic gained support for the offset= and skip= options in /etc/crypttab, as previously implemented by Debian.
/usr/lib/os-release gained a new optional field VARIANT= for distributions that support multiple variants (such as a desktop edition, a server edition, ...)

New in systemd 219 (Feb 17, 2015)

Introduce a new API "sd-hwdb.h" for querying the hardware metadata database. With this minimal interface one can query and enumerate the udev hwdb, decoupled from the old libudev library. libudev's interface for this is now only a wrapper around sd-hwdb. A new tool systemd-hwdb has been added to interface with and update the database.
When any of systemd's tools copies files (for example due to tmpfiles' C lines) a btrfs reflink will attempted first, before bytewise copying is done.
systemd-nspawn gained a new --ephemeral switch. When specified a btrfs snapshot is taken of the container's root directory, and immediately removed when the container terminates again. Thus, a container can be started whose changes never alter the container's root directory, and are lost on container termination. This switch can also be used for starting a container off the root file system of the host without affecting the host OS. This switch is only available on btrfs file systems.
systemd-nspawn gained a new --template= switch. It takes the path to a container tree to use as template for the tree specified via --directory=, should that directory be missing. This allows instantiating containers dynamically, on first run. This switch is only available on btrfs file systems.
When a .mount unit refers to a mount point on which multiple mounts are stacked, and the .mount unit is stopped all of the stacked mount points will now be unmounted until no mount point remains.
systemd now has an explicit notion of supported and unsupported unit types. Jobs enqueued for unsupported unit types will now fail with an "unsupported" error code. More specifically .swap, .automount and .device units are not supported in containers, .busname units are not supported on non-kdbus systems. .swap and .automount are also not supported if their respective kernel compile time options are disabled.
machinectl gained support for two new "copy-from" and "copy-to" commands for copying files from a running container to the host or vice versa.
machinectl gained support for a new "bind" command to bind mount host directories into local containers. This is currently only supported for nspawn containers.
networkd gained support for configuring bridge forwarding database entries (fdb) from .network files.
A new tiny daemon "systemd-importd" has been added that can download container images in tar, raw, qcow2 or dkr formats, and make them available locally in /var/lib/machines, so that they can run as nspawn containers. The daemon can GPG verify the downloads (not supported for dkr, since it has no provisions for verifying downloads). It will transparently decompress bz2, xz, gzip compressed downloads if necessary, and restore sparse files on disk. The daemon uses privilege separation to ensure the actual download logic runs with fewer privileges than the deamon itself. machinectl has gained new commands "pull-tar", "pull-raw" and "pull-dkr" to make the functionality of importd available to the user. With this in place the Fedora and Ubuntu "Cloud" images can be downloaded and booted as containers unmodified (the Fedora images lack the appropriate GPG signature files currently, so they cannot be verified, but this will change soon, hopefully). Note that downloading images is currently only fully supported on btrfs.
machinectl is now able to list container images found in /var/lib/machines, along with some metadata about sizes of disk and similar. If the directory is located on btrfs and quota is enabled, this includes quota display. A new command "image-status" has been added that shows additional information about images.
machinectl is now able to clone container images efficiently, if the underlying file system (btrfs) supports it, with the new "machinectl list-images" command. It also gained commands for renaming and removing images, as well as marking them read-only or read-write (supported also on legacy file systems).
networkd gained support for collecting LLDP network announcements, from hardware that supports this. This is shown in networkctl output.
systemd-run gained support for a new -t (--pty) switch for invoking a binary on a pty whose input and output is connected to the invoking terminal. This allows executing processes as system services while interactively communicating with them via the terminal. Most interestingly this is supported across container boundaries. Invoking "systemd-run -t /bin/bash" is an alternative to running a full login session, the difference being that the former will not register a session, nor go through the PAM session setup.
tmpfiles gained support for a new "v" line type for creating btrfs subvolumes. If the underlying file system is a legacy file system, this automatically degrades to creating a normal directory. Among others /var/lib/machines is now created like this at boot, should it be missing.
The directory /var/lib/containers/ has been deprecated and been replaced by /var/lib/machines. The term "machines" has been used in the systemd context as generic term for both VMs and containers, and hence appears more appropriate for this, as the directory can also contain raw images bootable via qemu/kvm.
systemd-nspawn when invoked with -M but without --directory= or --image= is now capable of searching for the container root directory, subvolume or disk image automatically, in /var/lib/machines. systemd-nspawn at .service has been updated to make use of this, thus allowing it to be used for raw disk images, too.
A new machines.target unit has been introduced that is supposed to group all containers/VMs invoked as services on the system. systemd-nspawn at .service has been updated to integrate with that.
machinectl gained a new "start" command, for invoking a container as a service. "machinectl start foo" is mostly equivalent to "systemctl start systemd-nspawn at foo.service", but handles escaping in a nicer way.
systemd-nspawn will now mount most of the cgroupfs tree read-only into each container, with the exception of the container's own subtree in the name=systemd hierarchy.
journald now sets the special FS_NOCOW file flag for its journal files. This should improve performance on btrfs, by avoiding heavy fragmentation when journald's write-pattern is used on COW file systems. It degrades btrfs' data integrity guarantees for the files to the same levels as for ext3/ext4 however. This should be OK though as journald does its own data integrity checks and all its objects are checksummed on disk. Also, journald should handle btrfs disk full events a lot more gracefully now, by processing SIGBUS errors, and not relying on fallocate() anymore.
When journald detects that journal files it is writing to have been deleted it will immediately start new journal files.
systemd now provides a way to store file descriptors per-service in PID 1.This is useful for daemons to ensure that fds they require are not lost during a daemon restart. The fds are passed to the deamon on the next invocation in the same way socket activation fds are passed. This is now used by journald to ensure that the various sockets connected to all the system's stdout/stderr are not lost when journald is restarted. File descriptors may be stored in PID 1 via the sd_pid_notify_with_fds() API, an extension to sd_notify(). Note that a limit is enforced on the number of fds a service can store in PID 1, and it defaults to 0, so that no fds may be stored, unless this is explicitly turned on.
The default TERM variable to use for units connected to a terminal, when no other value is explicitly is set is now vt220 rather than vt102. This should be fairly safe still, but allows PgUp/PgDn work.
The /etc/crypttab option header= as known from Debian is now supported.
"loginctl user-status" and "loginctl session-status" will now show the last 10 lines of log messages of the user/session following the status output. Similar, "machinectl status" will show the last 10 log lines associated with a virtual machine or container service. (Note that this is usually not the log messages done in the VM/container itself, but simply what the container manager logs. For nspawn this includes all console output however.)
"loginctl session-status" without further argument will now show the status of the session of the caller. Similar, "lock-session", "unlock-session", "activate", "enable-linger", "disable-linger" may now be called without session/user parameter in which case they apply to the caller's session/user.
An X11 session scriptlet is now shipped that uploads $DISPLAY and $XAUTHORITY into the environment of the systemd --user daemon if a session begins. This should improve compatibility with X11 enabled applications run as systemd user services.
Generators are now subject to masking via /etc and /run, the same way as unit files.
networkd .network files gained support for configuring per-link IPv4/IPv6 packet forwarding as well as IPv4 masquerading. This is by default turned on for veth links to containers, as registered by systemd-nspawn. This means that nspawn containers run with --network-veth will now get automatic routed access to the host's networks without any further configuration or setup, as long as networkd runs on the host.
systemd-nspawn gained the --port= (-p) switch to expose TCP or UDP posts of a container on the host. With this in place it is possible to run containers with private veth links (--network-veth), and have their functionality exposed on the host as if their services were running directly on the host.
systemd-nspawn's --network-veth switch now gained a short version "-n", since with the changes above it is now truly useful out-of-the-box. The systemd-nspawn at .service has been updated to make use of it too by default.
systemd-nspawn will now maintain a per-image R/W lock, to ensure that the same image is not started more than once writable. (It's OK to run an image multiple times simultaneously in read-only mode.)
systemd-nspawn's --image= option is now capable of dissecting and booting MBR and GPT disk images that contain only a single active Linux partition. Previously it supported only GPT disk images with proper GPT type IDs. This allows running cloud images from major distributions directly with systemd-nspawn, without modification.
In addition to collecting mouse dpi data in the udev hardware database, there's now support for collecting angle information for mouse scroll wheels. The database is supposed to guarantee similar scrolling behavior on mice that it knows about. There's also support for collecting information about Touchpad types.
udev's input_id built-in will now also collect touch screen dimension data and attach it to probed devices.
/etc/os-release gained support for a Distribution Privacy Policy link field.
networkd gained support for creating "ipvlan", "gretap", "ip6gre", "ip6gretap" and "ip6tnl" network devices.
systemd-tmpfiles gained support for "a" lines for setting ACLs on files.
systemd-nspawn will now mount /tmp in the container to tmpfs, automatically.
systemd now exposes the memory.usage_in_bytes cgroup attribute and shows it for each service in the "systemctl status" output, if available.
When the user presses Ctrl-Alt-Del more than 7x within 2s an immediate reboot is triggered. This useful if shutdown is hung and is unable to complete, to expedite the operation. Note that this kind of reboot will still unmount all file systems, and hence should not result in fsck being run on next reboot.
A .device unit for an optical block device will now be considered active only when a medium is in the drive. Also, mount units are now bound to their backing devices thus triggering automatic unmounting when devices become unavailable. With this in place systemd will now automatically unmount left-over mounts when a CD-ROM is ejected or an USB stick is yanked from the system.
networkd-wait-online now has support for waiting for specific interfaces only (with globbing), and for giving up after a configurable timeout.
networkd now exits when idle. It will be automatically restarted as soon as interfaces show up, are removed or change state. networkd will stay around as long as there is at least one DHCP state machine or similar around, that keep it non-idle.
networkd may now configure IPv6 link-local addressing in addition to IPv4 link-local addressing.
The IPv6 "token" for use in SLAAC may now be configured for each .network interface in networkd.
Routes configured with networkd may now be assigned a scope in .network files.
networkd's [Match] sections now support globbing and lists of multiple space-separated matches per item.

New in systemd 218 (Dec 11, 2014)

When querying unit file enablement status (for example via "systemctl is-enabled"), a new state "indirect" is now known which indicates that a unit might not be enabled itself, but another unit listed in its Alias= setting might be.
Similar to the various existing ConditionXYZ= settings for units there are now matching AssertXYZ= settings. While failing conditions cause a unit to be skipped, but its job to succeed, failing assertions declared like this will cause a unit start operation and its job to fail.
hostnamed now knows a new chassis type "embedded".
systemctl gained a new "edit" command. When used on a unit file this allows extending unit files with .d/ drop-in configuration snippets or editing the full file (after copying it from /usr/lib to /etc). This will invoke the user's editor (as configured with $EDITOR), and reload the modified configuration after editing.
"systemctl status" now shows the suggested enablement state for a unit, as declared in the (usually vendor-supplied) system preset files.
nss-myhostname will now resolve the single-label host name "gateway" to the locally configured default IP routing gateways, ordered by their metrics. This assigns a stable name to the used gateways, regardless which ones are currently configured. Note that the name will only be resolved after all other name sources (if nss-myhostname is configured properly) and should hence not negatively impact systems that use the single-label host name "gateway" in other contexts.
systemd-inhibit now allows filtering by mode when listing inhibitors.
Scope and service units gained a new "Delegate" boolean property, which when set allows processes running inside the unit to further partition resources. This is primarily useful for systemd user instances as well as container managers.
journald will now pick up audit messages directly from the kernel, and log them like any other log message. The audit fields are split up and fully indexed. This means that journalctl in many ways is now a (nicer!) alternative to ausearch, the traditional audit client. Note that this implements only a minimal audit client, if you want the special audit modes like reboot-on-log-overflow, please use the traditional auditd instead, which can be used in parallel to journald.
The ConditionSecurity= unit file option now understands the special string "audit" to check whether auditing is available.
journalctl gained two new commands --vacuum-size= and --vacuum-time= to delete old journal files until the remaining ones take up no more the specified size on disk, or are not older than the specified time.
A new, native PPPoE library has been added to sd-network, systemd's library of light-weight networking protocols. This library will be used in a future version of networkd to enable PPPoE communication without an external pppd daemon.
The busctl tool now understands a new "capture" verb that works similar to "monitor", but writes a packet capture trace to STDOUT that can be redirected to a file which is compatible with libcap's capture file format. This can then be loaded in Wireshark and similar tools to inspect bus communication.
The busctl tool now understands a new "tree" verb that shows the object trees of a specific service on the bus, or of all services.
The busctl tool now understands a new "introspect" verb that shows all interfaces and members of objects on the bus, including their signature and values. This is particularly useful to get more information about bus objects shown by the new "busctl tree" command.
The busctl tool now understands new verbs "call", "set-property" and "get-property" for invoking bus method calls, setting and getting bus object properties in a friendly way.
busctl gained a new --augment-creds= argument that controls whether the tool shall augment credential information it gets from the bus with data from /proc, in a possibly race-ful way.
nspawn's --link-journal= switch gained two new values "try-guest" and "try-host" that work like "guest" and "host", but do not fail if the host has no persistent journalling enabled. -j is now equivalent to --link-journal=try-guest.
macvlan network devices created by nspawn will now have stable MAC addresses.
A new SmackProcessLabel= unit setting has been added, which controls the SMACK security label processes forked off by the respective unit shall use.
If compiled with --enable-xkbcommon, systemd-localed will verify x11 keymap settings by compiling the given keymap. It will spew out warnings if the compilation fails. This requires libxkbcommon to be installed.
When a coredump is collected a larger number of metadata fields is now collected and included in the journal records created for it. More specifically control group membership, environment variables, memory maps, working directory, chroot directory, /proc/$PID/status, and a list of open file descriptors is now stored in the log entry.
The udev hwdb now contains DPI information for mice. For details see: http://who-t.blogspot.de/2014/12/building-a-dpi-database-for-mice.html
All systemd programs that read standalone configuration files in /etc now also support a corresponding series of .conf.d configuration directories in /etc/, /run/, /usr/local/lib/, /usr/lib/, and (if configured with --enable-split-usr) /lib/. In particular, the following configuration files now have corresponding configuration directories: system.conf user.conf, logind.conf, journald.conf, sleep.conf, bootchart.conf, coredump.conf, resolved.conf, timesyncd.conf, journal-remote.conf, and journal-upload.conf. Note that distributions should use the configuration directories in /usr/lib/; the directories in /etc/ are reserved for the system administrator.
systemd-rfkill will no longer take the rfkill device name into account when storing rfkill state on disk, as the name might be dynamically assigned and not stable. Instead, the ID_PATH udev variable combined with the rfkill type (wlan, bluetooth, ...) is used.
A new service systemd-machine-id-commit.service has been added. When used on systems where /etc is read-only during boot, and /etc/machine-id is not initialized (but an empty file), this service will copy the temporary machine ID created as replacement into /etc after the system is fully booted up. This is useful for systems that are freshly installed with a non-initialized machine ID, but should get a fixed machine ID for subsequent boots.
networkd's .netdev files now provide a large set of configuration parameters for VXLAN devices. Similar, the bridge port cost parameter is now configurable in .network files. There's also new support for configuring IP source routing. networkd .link files gained support for a new OriginalName= match that is useful to match against the original interface name the kernel assigned. .network files may include MTU= and MACAddress= fields for altering the MTU and MAC address while being connected to a specific network interface.
The LUKS logic gained supported for configuring UUID-specific key files. There's also new support for naming LUKS device from the kernel command line, using the new luks.name= argument.
Timer units may now be transiently created via the bus API (this was previously already available for scope and service units). In addition it is now possible to create multiple transient units at the same time with a single bus call. The "systemd-run" tool has been updated to make use of this for running commands on a specified time, in at(1)-style.
tmpfiles gained support for "t" lines, for assigning extended attributes to files. Among other uses this may be used to assign SMACK labels to files.

New in systemd 217 (Oct 28, 2014)

journalctl gained the new options -t/--identifier= to match on the syslog identifier (aka "tag"), as well as --utc to show log timestamps in the UTC timezone. journalctl now also accepts -n/--lines=all to disable line capping in a pager.
Services can notify the manager before they start a reload (by sending RELOADING=1) or shutdown (by sending STOPPING=1). This allows the manager to track and show the internal state of daemons and closes a race condition when the process is still running but has closed its D-Bus connection.
Services with Type=oneshot do not have to have any ExecStart commands anymore.
User units are now loaded also from $XDG_RUNTIME_DIR/systemd/user/. This is similar to the /run/systemd/user directory that was already previously supported, but is under the control of the user.
Job timeouts (i.e. time-outs on the time a job that is queued stays in the run queue) can now optionally result in immediate reboot or power-off actions (JobTimeoutAction= and JobTimeoutRebootArgument=). This is useful on ".target" units, to limit the maximum time a target remains undispatched in the run queue, and to trigger an emergency operation in such a case. This is now used by default to turn off the system if boot-up (as defined by everything in basic.target) hangs and does not complete for at least 15min. Also, if power-off or reboot hang for at least 30min an immediate power-off/reboot operation is triggered. This functionality is particularly useful to increase reliability on embedded devices, but also on laptops which might accidentally get powered on when carried in a backpack and whose boot stays stuck in a hard disk encryption passphrase question.
systemd-logind can be configured to also handle lid switch events even when the machine is docked or multiple displays are attached (HandleLidSwitchDocked= option).
A helper binary and a service have been added which can be used to resume from hibernation in the initramfs. A generator will parse the resume= option on the kernel command-line to trigger resume.
A user console daemon systemd-consoled has been added. Currently, it is a preview, and will so far open a single terminal on each session of the user marked as Desktop=systemd-console.
Route metrics can be specified for DHCP routes added by systemd-networkd.
The SELinux context of socket-activated services can be set from the information provided by the networking stack (SELinuxContextFromNet= option).
Userspace firmware loading support has been removed and the minimum supported kernel version is thus bumped to 3.7.
Timeout for udev workers has been increased from 1 to 3 minutes, but a warning will be printed after 1 minute to help diagnose kernel modules that take a long time to load.
Udev rules can now remove tags on devices with TAG-="foobar".
systemd's readahead implementation has been removed. In many circumstances it didn't give expected benefits even for rotational disk drives and was becoming less relevant in the age of SSDs. As none of the developers has been using rotating media anymore, and nobody stepped up to actively maintain this component of systemd it has now been removed.
Swap units can use Discard= to specify discard options. Discard options specified for swaps in /etc/fstab are now respected.
Docker containers are now detected as a separate type of virtualization.
The Password Agent protocol gained support for queries where the user input is shown, useful e.g. for user names. systemd-ask-password gained a new --echo option to turn that on.
The default sysctl.d/ snippets will now set: net.core.default_qdisc = fq_codel This selects Fair Queuing Controlled Delay as the default queuing discipline for network interfaces. fq_codel helps fight the network bufferbloat problem. It is believed to be a good default with no tuning required for most workloads. Downstream distributions may override this choice. On 10Gbit servers that do not do forwarding, "fq" may perform better. Systems without a good clocksource should use "pfifo_fast".
If kdbus is enabled during build a new option BusPolicy= is available for service units, that allows locking all service processes into a stricter bus policy, in order to limit access to various bus services, or even hide most of them from the service's view entirely.
networkctl will now show the .network and .link file networkd has applied to a specific interface.
sd-login gained a new API call sd_session_get_desktop() to query which desktop environment has been selected for a session.
UNIX utmp support is now compile-time optional to support legacy-free systems.
systemctl gained two new commands "add-wants" and "add-requires" for pulling in units from specific targets easily.
If the word "rescue" is specified on the kernel command line the system will now boot into rescue mode (aka rescue.target), which was previously available only by specifying "1" or "systemd.unit=rescue.target" on the kernel command line. This new kernel command line option nicely mirrors the already existing "emergency" kernel command line option.
New kernel command line options mount.usr=, mount.usrflags=, mount.usrfstype= have been added that match root=, rootflags=, rootfstype= but allow mounting a specific file system to /usr.
The $NOTIFY_SOCKET is now also passed to control processes of services, not only the main process.
This version reenables support for fsck's -l switch. This means at least version v2.25 of util-linux is required for operation, otherwise dead-locks on device nodes may occur. Again: you need to update util-linux to at least v2.25 when updating systemd to v217.
The "multi-seat-x" tool has been removed from systemd, as its functionality has been integrated into X servers 1.16, and the tool is hence redundant. It is recommended to update display managers invoking this tool to simply invoke X directly from now on, again.
Support for the new ALLOW_INTERACTIVE_AUTHORIZATION D-Bus message flag has been added for all of systemd's PolicyKit authenticated method calls has been added. In particular this now allows optional interactive authorization via PolicyKit for many of PID1's privileged operations such as unit file enabling and disabling.
"udevadm hwdb --update" learnt a new switch "--usr" for placing the rebuilt hardware database in /usr instead of /etc. When used only hardware database entries stored in /usr will be used, and any user database entries in /etc are ignored. This functionality is useful for vendors to ship a pre-built database on systems where local configuration is unnecessary or unlikely.
Calendar time specifications in .timer units now also understand the strings "semi-annually", "quarterly" and "minutely" as shortcuts (in addition to the preexisting "anually", "hourly", ...).
systemd-tmpfiles will now correctly create files in /dev at boot which are marked for creation only at boot. It is recommended to always create static device nodes with 'c!' and 'b!', so that they are created only at boot and not overwritten at runtime.
When the watchdog logic is used for a service (WatchdogSec=) and the watchdog timeout is hit the service will now be terminated with SIGABRT (instead of just SIGTERM), in order to make sure a proper coredump and backtrace is generated. This ensures that hanging services will result in similar coredump/backtrace behaviour as services that hit a segmentation fault.

New in systemd 216 (Aug 20, 2014)

timedated no longer reads NTP implementation unit names from /usr/lib/systemd/ntp-units.d/*.list. Alternative NTP implementations should add a Conflicts=systemd-timesyncd.service to their unit files to take over and replace systemd's NTP default functionality.
systemd-sysusers gained a new line type "r" for configuring which UID/GID ranges to allocate system users/groups from. Lines of type "u" may now add an additional column that specifies the home directory for the system user to be created. Also, systemd-sysusers may now optionally read user information from STDIN instead of a file. This is useful for invoking it from RPM preinst scriptlets that need to create users before the first RPM file is installed since these files might need to be owned by them. A new %sysusers_create_inline RPM macro has been introduced to do just that. systemd-sysusers now updates the shadow files as well as the user/group databases, which should enhance compatibility with certain tools like grpck.
A number of bus APIs of PID 1 now optionally consult PolicyKit to permit access for otherwise unprivileged clients under certain conditions. Note that this currently doesn't support interactive authentication yet, but this is expected to be added eventually, too.
/etc/machine-info now has new fields for configuring the deployment environment of the machine, as well as the location of the machine. hostnamectl has been updated with new command to update these fields.
systemd-timesyncd has been updated to automatically acquire NTP server information from systemd-networkd, which might have been discovered via DHCP.
systemd-resolved now includes a caching DNS stub resolver and a complete LLMNR name resolution implementation. A new NSS module "nss-resolve" has been added which make be used of glibc's own "nss-dns" to resolve hostnames via systemd-resolved. Hostnames, addresses and arbitrary RRs may be resolved via systemd-resolved D-Bus APIs. In contrast to the glibc internal resolver systemd-resolved is aware of multi-homed system, and keeps DNS server and caches separate and per-interface. Queries are sent simultaneously on all interfaces that have DNS servers configured, in order to properly handle VPNs and local LANs which might resolve separate sets of domain names. systemd-resolved may acquire DNS server information from systemd-networkd automatically, which in turn might have discovered them via DHCP. A tool "systemd-resolve-host" has been added that may be used to query the DNS logic in resolved. systemd-resolved implements IDNA and automatically uses IDNA or UTF-8 encoding depending on whether classic DNS or LLMNR is used as transport. In the next releases we intend to add a DNSSEC and mDNS/DNS-SD implementation to systemd-resolved.
A new NSS module nss-mymachines has been added, that automatically resolves the names of all local registered containers to their respective IP addresses.
A new client tool "networkctl" for systemd-networkd has been added. It currently is entirely passive and will query networking configuration from udev, rtnetlink and networkd, and present it to the user in a very friendly way. Eventually, we hope to extend it to become a full control utility for networkd.
.socket units gained a new DeferAcceptSec= setting that controls the kernels' TCP_DEFER_ACCEPT sockopt for TCP. Similar, support for controlling TCP keep-alive settings has been added (KeepAliveTimeSec=, KeepAliveIntervalSec=, KeepAliveProbes=). Also, support for turning off Nagle's algorithm on TCP has been added (NoDelay=).
logind learned a new session type "web", for use in projects like Cockpit which register web clients as PAM sessions.
timer units with at least one OnCalendar= setting will now be started only after timer-sync.target has been reached. This way they will not elapse before the system clock has been corrected by a local NTP client or similar. This is particular useful on RTC-less embedded machines, that come up with an invalid system clock.
systemd-nspawn's --network-veth= switch should now result in stable MAC addresses for both the outer and the inner side of the link.
systemd-nspawn gained a new --volatile= switch for running container instances with /etc or /var unpopulated.
The kdbus client code has been updated to use the new Linux 3.17 memfd subsystem instead of the old kdbus-specific one.
systemd-networkd's DHCP client and server now support FORCERENEW. There are also new configuration options to configure the vendor client identifier and broadcast mode for DHCP.
systemd will no longer inform the kernel about the current timezone, as this is necessarily incorrect and racy as the kernel has no understanding of DST and similar concepts. This hence means FAT timestamps will be always considered UTC, similar to what Android is already doing. Also, when the RTC is configured to the local time (rather than UTC) systemd will never synchronize back to it, as this might confuse Windows at a later boot.
systemd-analyze gained a new command "verify" for offline validation of unit files.
systemd-networkd gained support for a couple of additional settings for bonding networking setups. Also, the metric for statically configured routes may now be configured. For network interfaces where this is appropriate the peer IP address may now be configured.
systemd-networkd's DHCP client will no longer request broadcasting by default, as this tripped up some networks. For hardware where broadcast is required the feature should be switched back on using RequestBroadcast=yes.
systemd-networkd will now set up IPv4LL addresses (when enabled) even if DHCP is configured successfully.
udev will now default to respect network device names given by the kernel when the kernel indicates that these are predictable. This behavior can be tweaked by changing NamePolicy= in the relevant .link file.
A new library systemd-terminal has been added that implements full TTY stream parsing and rendering. This library is supposed to be used later on for implementing a full userspace VT subsystem, replacing the current kernel implementation.
A new tool systemd-journal-upload has been added to push journal data to a remote system running systemd-journal-remote.
journald will no longer forward all local data to another running syslog daemon. This change has been made because rsyslog (which appears to be the most commonly used syslog implementation these days) no longer makes use of this, and instead pulls the data out of the journal on its own. Since forwarding the messages to a non-existent syslog server is more expensive than we assumed we have now turned this off. If you run a syslog server that is not a recent rsyslog version, you have to turn this option on again (ForwardToSyslog= in journald.conf).
journald now optionally supports the LZ4 compressor for larger journal fields. This compressor should perform much better than XZ which was the previous default.
machinectl now shows the IP addresses of local containers, if it knows them, plus the interface name of the container.
A new tool "systemd-escape" has been added that makes it easy to escape strings to build unit names and similar.
sd_notify() messages may now include a new ERRNO= field which is parsed and collected by systemd and shown among the "systemctl status" output for a service.
A new component "systemd-firstboot" has been added that queries the most basic systemd information (timezone, hostname, root password) interactively on first boot. Alternatively it may also be used to provision these things offline on OS images installed into directories.
The default sysctl.d/ snippets will now set net.ipv4.conf.default.promote_secondaries=1 This has the benefit of no flushing secondary IP addresses when primary addresses are removed.

New in systemd 215 (Jul 4, 2014)

A new tool systemd-sysusers has been added. This tool creates system users and groups in /etc/passwd and /etc/group, based on static declarative system user/group definitions in /usr/lib/sysusers.d/. This is useful to enable factory resets and volatile systems that boot up with an empty /etc directory, and thus need system users and groups created during early boot. systemd now also ships with two default sysusers.d/ files for the most basic users and groups systemd and the core operating system require.
A new tmpfiles snippet has been added that rebuilds the essential files in /etc on boot, should they be missing.
A directive for ensuring automatic clean-up of /var/cache/man/ has been removed from the default configuration. This line should now be shipped by the man implementation. The necessary change has been made to the man-db implementation. Note that you need to update your man implementation to one that ships this line, otherwise no automatic clean-up of /var/cache/man will take place.
A new condition ConditionNeedsUpdate= has been added that may conditionalize services to only run when /etc or /var are "older" than the vendor operating system resources in /usr. This is useful for reconstructing or updating /etc after an offline update of /usr or a factory reset, on the next reboot. Services that want to run once after such an update or reset should use this condition and order themselves before the new systemd-update-done.service, which will mark the two directories as fully updated. A number of service files have been added making use of this, to rebuild the udev hardware database, the journald message catalog and dynamic loader cache (ldconfig). The systemd-sysusers tool described above also makes use of this now. With this in place it is now possible to start up a minimal operating system with /etc empty cleanly. For more information on the concepts involved see this recent blog story: http://0pointer.de/blog/projects/stateless.html
A new system group "input" has been introduced, and all input device nodes get this group assigned. This is useful for system-level software to get access to input devices. It complements what is already done for "audio" and "video".
systemd-networkd learnt minimal DHCPv4 server support in addition to the existing DHCPv4 client support. It also learnt DHCPv6 client and IPv6 Router Solicitation client support. The DHCPv4 client gained support for static routes passed in from the server. Note that the [DHCPv4] section known in older systemd-networkd versions has been renamed to [DHCP] and is now also used by the DHCPv6 client. Existing .network files using settings of this section should be updated, though compatibility is maintained. Optionally, the client hostname may now be sent to the DHCP server.
networkd gained support for vxlan virtual networks as well as tun/tap and dummy devices.
networkd gained support for automatic allocation of address ranges for interfaces from a system-wide pool of addresses. This is useful for dynamically managing a large number of interfaces with a single network configuration file. In particular this is useful to easily assign appropriate IP addresses to the veth links of a large number of nspawn instances.
RPM macros for processing sysusers, sysctl and binfmt drop-in snippets at package installation time have been added.
The /etc/os-release file should now be placed in /usr/lib/os-release. The old location is automatically created as symlink. /usr/lib is the more appropriate location of this file, since it shall actually describe the vendor operating system shipped in /usr, and not the configuration stored in /etc.
.mount units gained a new boolean SloppyOptions= setting that maps to mount(8)'s -s option which enables permissive parsing of unknown mount options.
tmpfiles learnt a new "L+" directive which creates a symlink but (unlike "L") deletes a pre-existing file first, should it already exist and not already be the correct symlink. Similar, "b+", "c+" and "p+" directives have been added as well, which create block and character devices, as well as fifos in the filesystem, possibly removing any pre-existing files of different types.
For tmpfiles' "L", "L+", "C" and "C+" directives the final 'argument' field (which so far specified the source to symlink/copy the files from) is now optional. If omitted the same file os copied from /usr/share/factory/ suffixed by the full destination path. This is useful for populating /etc with essential files, by copying them from vendor defaults shipped in /usr/share/factory/etc.
A new command "systemctl preset-all" has been added that applies the service preset settings to all installed unit files. A new switch --preset-mode= has been added that controls whether only enable or only disable operations shall be executed.
A new command "systemctl is-system-running" has been added that allows checking the overall state of the system, for example whether it is fully up and running.
When the system boots up with an empty /etc, the equivalent to "systemctl preset-all" is executed during early boot, to make sure all default services are enabled after a factory reset.
systemd now contains a minimal preset file that enables the most basic services systemd ships by default.
Unit files' [Install] section gained a new DefaultInstance= field for defining the default instance to create if a template unit is enabled with no instance specified.
A new passive target cryptsetup-pre.target has been added that may be used by services that need to make they run and finish before the first LUKS cryptographic device is set up.
The /dev/loop-control and /dev/btrfs-control device nodes are now owned by the "disk" group by default, opening up access to this group.
systemd-coredump will now automatically generate a stack trace of all core dumps taking place on the system, based on elfutils' libdw library. This stack trace is logged to the journal.
systemd-coredump may now optionally store coredumps directly on disk (in /var/lib/systemd/coredump, possibly compressed), instead of storing them unconditionally in the journal. This mode is the new default. A new configuration file /etc/systemd/coredump.conf has been added to configure this and other parameters of systemd-coredump.
coredumpctl gained a new "info" verb to show details about a specific coredump. A new switch "-1" has also been added that makes sure to only show information about the most recent entry instead of all entries. Also, as the tool is generally useful now the "systemd-" prefix of the binary name has been removed. Distributions that want to maintain compatibility with the old name should add a symlink from the old name to the new name.
journald's SplitMode= now defaults to "uid". This makes sure that unprivileged users can access their own coredumps with coredumpctl without restrictions.
New kernel command line options "systemd.wants=" (for pulling an additional unit during boot), "systemd.mask=" (for masking a specific unit for the boot), and "systemd.debug-shell" (for enabling the debug shell on tty9) have been added. This is implemented in the new generator "systemd-debug-generator".
systemd-nspawn will now by default filter a couple of syscalls for containers, among them those required for kernel module loading, direct x86 IO port access, swap management, and kexec. Most importantly though open_by_handle_at() is now prohibited for containers, closing a hole similar to a recently discussed vulnerability in docker regarding access to files on file hierarchies the container should normally not have access to. Note that for nspawn we generally make no security claims anyway (and this is explicitly documented in the man page), so this is just a fix for one of the most obvious problems.
A new man page file-hierarchy(7) has been added that contains a minimized, modernized version of the file system layout systemd expects, similar in style to the FHS specification or hier(5). A new tool systemd-path(1) has been added to query many of these paths for the local machine and user.
Automatic time-based clean-up of $XDG_RUNTIME_DIR is no longer done. Since the directory now has a per-user size limit, and is cleaned on logout this appears unnecessary, in particular since this now brings the lifecycle of this directory closer in line with how IPC objects are handled.
systemd.pc now exports a number of additional directories, including $libdir (which is useful to identify the library path for the primary architecture of the system), and a couple of drop-in directories.
udev's predictable network interface names now use the dev_port sysfs attribute, introduced in linux 3.15 instead of dev_id to distinguish between ports of the same PCI function. dev_id should only be used for ports using the same HW address, hence the need for dev_port.
machined has been updated to export the OS version of a container (read from /etc/os-release and /usr/lib/os-release) on the bus. This is now shown in "machinectl status" for a machine.
A new service setting RestartForceExitStatus= has been added. If configured to a set of exit signals or process return values, the service will be restarted when the main daemon process exits with any of them, regardless of the Restart= setting.
systemctl's -H switch for connecting to remote systemd machines has been extended so that it may be used to directly connect to a specific container on the host. "systemctl -H root at foobar:waldi" will now connect as user "root" to host "foobar", and then proceed directly to the container named "waldi". Note that currently you have to authenticate as user "root" for this to work, as entering containers is a privileged operation.

New in systemd 213 (May 28, 2014)

A new "systemd-timesyncd" daemon has been added for synchronizing the system clock across the network. It implements an SNTP client. In contrast to NTP implementations such as chrony or the NTP reference server this only implements a client side, and does not bother with the full NTP complexity, focusing only on querying time from one remote server and synchronizing the local clock to it. Unless you intend to serve NTP to networked clients or want to connect to local hardware clocks this simple NTP client should be more than appropriate for most installations. The daemon runs with minimal privileges, and has been hooked up with networkd to only operate when network connectivity is available. The daemon saves the current clock to disk every time a new NTP sync has been acquired, and uses this to possibly correct the system clock early at bootup, in order to accommodate for systems that lack an RTC such as the Raspberry Pi and embedded devices, and make sure that time monotonically progresses on these systems, even if it is not always correct. To make use of this daemon a new system user and group "systemd-timesync" needs to be created on installation of systemd.
The queue "seqnum" interface of libudev has been disabled, as it was generally incompatible with device namespacing as sequence numbers of devices go "missing" if the devices are part of a different namespace.
"systemctl list-timers" and "systemctl list-sockets" gained a --recursive switch for showing units of these types also for all local containers, similar in style to the already supported --recursive switch for "systemctl list-units".
A new RebootArgument= setting has been added for service units, which may be used to specify a kernel reboot argument to use when triggering reboots with StartLimitAction=.
A new FailureAction= setting has been added for service units which may be used to specify an operation to trigger when a service fails. This works similarly to StartLimitAction=, but unlike it controls what is done immediately rather than only after several attempts to restart the service in question.
hostnamed got updated to also expose the kernel name, release, and version on the bus. This is useful for executing commands like hostnamectl with the -H switch. systemd-analyze makes use of this to properly display details when running non-locally.
The bootchart tool can now show cgroup information in the graphs it generates.
The CFS CPU quota cgroup attribute is now exposed for services. The new CPUQuota= switch has been added for this which takes a percentage value. Setting this will have the result that a service may never get more CPU time than the specified percentage, even if the machine is otherwise idle.
systemd-networkd learned IPIP and SIT tunnel support.
LSB init scripts exposing a dependency on $network will now get a dependency on network-online.target rather than simply network.target. This should bring LSB handling closer to what it was on SysV systems.
A new fsck.repair= kernel option has been added to control how fsck shall deal with unclean file systems at boot.
The (.ini) configuration file parser will now silently ignore sections whose name begins with "X-". This may be used to maintain application-specific extension sections in unit files.
machined gained a new API to query the IP addresses of registered containers. "machinectl status" has been updated to show these addresses in its output.
A new call sd_uid_get_display() has been added to the sd-login APIs for querying the "primary" session of a user. The "primary" session of the user is elected from the user's sessions and generally a graphical session is preferred over a text one.
A minimal systemd-resolved daemon has been added. It currently simply acts as a companion to systemd-networkd and manages resolv.conf based on per-interface DNS configuration, possibly supplied via DHCP. In the long run we hope to extend this into a local DNSSEC enabled DNS and mDNS cache.
The systemd-networkd-wait-online tool is now enabled by default. It will delay network-online.target until a network connection has been configured. The tool primarily integrates with networkd, but will also make a best effort to make sense of network configuration performed in some other way.
Two new service options StartupCPUShares= and StartupBlockIOWeight= have been added that work similarly to CPUShares= and BlockIOWeight= however only apply during system startup. This is useful to prioritize certain services differently during bootup than during normal runtime.
hostnamed has been changed to prefer the statically configured hostname in /etc/hostname (unless set to 'localhost' or empty) over any dynamic one supplied by dhcp. With this change the rules for picking the hostname match more closely the rules of other configuration settings where the local administrator's configuration in /etc always overrides any other settings.

New in systemd 212 (Mar 26, 2014)

When restoring the screen brightness at boot, stay away from the darkest setting or from the lowest 5% of the available range, depending on which is the larger value of both. This should effectively protect the user from rebooting into a black screen, should the brightness have been set to minimum by accident.
sd-login gained a new sd_machine_get_class() call to determine the class ("vm" or "container") of a machine registered with machined.
sd-login gained new calls sd_peer_get_{session,owner_uid,unit,user_unit,slice,machine_name}(), to query the identity of the peer of a local AF_UNIX connection. They operate similar to their sd_pid_get_xyz() counterparts.
PID 1 will now maintain a system-wide system state engine with the states "starting", "running", "degraded", "maintenance", "stopping". These states are bound to system startup, normal runtime, runtime with at least one failed service, rescue/emergency mode and system shutdown. This state is shown in the "systemctl status" output when no unit name is passed. It is useful to determine system state, in particularly when doing so for many systems or containers at once.
A new command "list-machines" has been added to "systemctl" that lists all local OS containers and shows their system state (see above), if systemd runs inside of them.
systemctl gained a new "-r" switch to recursively enumerate units on all local containers, when used with the "list-unit" command (which is the default one that is executed when no parameters are specified).
The GPT automatic partition discovery logic will now honour two GPT partition flags: one may be set on a partition to cause it to be mounted read-only, and the other may be set on a partition to ignore it during automatic discovery.
Two new GPT type UUIDs have been added for automatic root partition discovery, for 32bit and 64bit ARM. This is not particularly useful for discovering the root directory on these architectures during bare-metal boots (since UEFI is not common there), but still very useful to allow booting of ARM disk images in nspawn with the -i option.
MAC addresses of interfaces created with nspawn's --network-interface= switch will now be generated from the machine name, and thus be stable between multiple invocations of the container.
logind will now automatically remove all IPC objects owned by a user if she or he fully logs out. This makes sure that users who are logged out cannot continue to consume IPC resources. This covers SysV memory, semaphores and message queues as well as POSIX shared memory and message queues. Traditionally SysV and POSIX IPC had no life-cycle limits, with this functionality this is corrected. This may be turned off using the RemoveIPC= switch of logind.conf.
The systemd-machine-id-setup and tmpfiles tools gained a --root= switch to operate on a specific root directory, instead of /.
journald can now forward logged messages to the TTYs of all logged in users ("wall"). This is the default for all emergency messages now.
A new tool systemd-journal-remote has been added to stream journal log messages across the network.
/sys/fs/cgroup/ is now mounted read-only after all cgroup controller trees are mounted into it. Note that the directories mounted beneath it are not read-only. This is a security measure and is particularly useful because glibc actually includes a search logic to pick any tmpfs it can find to implement shm_open() if /dev/shm is not available (which it might very well be in namespaced setups).
machinectl gained a new "poweroff" command to cleanly power down a local OS container.
The PrivateDevices= unit file setting will now also drop the CAP_MKNOD capability from the capability bound set, and imply DevicePolicy=closed.
PrivateDevices=, PrivateNetwork= and PrivateTmp= is now used comprehensively on all long-running systemd services where this is appropriate.
systemd-udevd will now run in a disassociated mount namespace. To mount directories from udev rules make sure to pull in mount units via SYSTEMD_WANTS properties.
The kdbus support gained support for uploading policy into the kernel. sd-bus gained support for creating "monitoring" connections that can eavesdrop into all bus communication for debugging purposes.
Timestamps may now be specified in seconds since the UNIX epoch Jan 1st, 1970 by specifying "@" followed by the value in seconds.
Native tcpwrap support in systemd has been removed. tcpwrap is old code, not really maintained anymore and has serious shortcomings, and better options such as firewalls exist. For setups that require tcpwrap usage, please consider invoking your socket-activated service via tcpd, like on traditional inetd.
A new system.conf configuration option DefaultTimerAccuracySec= has been added that controls the default AccuracySec= setting of .timer units.
Timer units gained a new WakeSystem= switch. If enabled timers configured this way will cause the system to resume from system suspend (if the system supports that, which most do these days).
Timer units gained a new Persistent= switch. If enabled timers configured this way will save to disk when they have been last triggered. This information is then used on next reboot to possible execute overdue timer events, that couldn't take place because the system was powered off. This enables simple anacron-like behaviour for timer units.
systemctl's "list-timers" will now also list the time a timer unit was last triggered in addition to the next time it will be triggered.
systemd-networkd will now assign predictable IPv4LL addresses to its local interfaces.

New in systemd 211 (Mar 12, 2014)

A new unit file setting RestrictAddressFamilies= has been added to restrict which socket address families unit processes gain access to. This takes address family names like "AF_INET" or "AF_UNIX", and is useful to minimize the attack surface of services via exotic protocol stacks. This is built on seccomp system call filters.
Two new unit file settings RuntimeDirectory= and RuntimeDirectoryMode= have been added that may be used to manage a per-daemon runtime directories below /run. This is an alternative for setting up directory permissions with tmpfiles snippets, and has the advantage that the runtime directory's lifetime is bound to the daemon runtime and that the daemon starts up with an empty directory each time. This is particularly useful when writing services that drop priviliges using the User= or Group= setting.
The DeviceAllow= unit setting now supports globbing for matching against device group names.
The systemd configuration file system.conf gained new settings DefaultCPUAccounting=, DefaultBlockIOAccounting=, DefaultMemoryAccounting= to globally turn on/off accounting for specific resources (cgroups) for all units. These settings may still be overridden individually in each unit though.
systemd-gpt-auto-generator is now able to discover /srv and root partitions in addition to /home and swap partitions. It also supports LUKS-encrypted partitions now. With this in place automatic discovery of partitions to mount following the Discoverable Partitions Specification (http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec) is now a lot more complete. This allows booting without /etc/fstab and without root= on the kernel command line on appropriately prepared systems.
systemd-nspawn gained a new --image= switch which allows booting up disk images and Linux installations on any block device that follow the Discoverable Partitions Specification (see above). This means that installations made with appropriately updated installers may now be started and deployed using container managers, completely unmodified. (We hope that libvirt-lxc will add support for this feature soon, too.)
systemd-nspawn gained a new --network-macvlan= setting to set up a private macvlan interface for the container. Similar, systemd-networkd gained a new Kind=macvlan setting in .netdev files.
systemd-networkd now supports configuring local addresses using IPv4LL.
A new tool systemd-network-wait-online has been added to synchronously wait for network connectivity using systemd-networkd.
The sd-bus.h bus API gained a new sd_bus_track object for tracking the life-cycle of bus peers. Note that sd-bus.h is still not a public API though (unless you specify --enable-kdbus on the configure command line, which however voids your warranty and you get no API stability guarantee).
The $XDG_RUNTIME_DIR runtime directories for each user are now individual tmpfs instances, which has the benefit of introducing separate pools for each user, with individual size limits, and thus making sure that unprivileged clients can no longer negatively impact the system or other users by filling up their $XDG_RUNTIME_DIR. A new logind.conf setting RuntimeDirectorySize= has been introduced that allows controlling the default size limit for all users. It defaults to 10% of the available physical memory. This is no replacement for quotas on tmpfs though (which the kernel still does not support), as /dev/shm and /tmp are still shared resources used by both the system and unprivileged users.
logind will now automatically turn off automatic suspending on laptop lid close when more than one display is connected. This was previously expected to be implemented individually in desktop environments (such as GNOME), however has been added to logind now, in order to fix a boot-time race where a desktop environment might not have been started yet and thus not been able to take an inhibitor lock at the time where logind already suspends the system due to a closed lid.
logind will now wait at least 30s after each system suspend/resume cycle, and 3min after system boot before suspending the system due to a closed laptop lid. This should give USB docking stations and similar enough time to be probed and configured after system resume and boot in order to then act as suspend blocker.
systemd-run gained a new --property= setting which allows initialization of resource control properties (and others) for the created scope or service unit. Example: "systemd-run --property=BlockIOWeight=10 updatedb" may be used to run updatedb at a low block IO scheduling weight.
systemd-run's --uid=, --gid=, --setenv=, --setenv= switches now also work in --scope mode.
When systemd is compiled with kdbus support, basic support for enforced policies is now in place. (Note that enabling kdbus still voids your warranty and no API compatibility promises are made.)

New in systemd 210 (Feb 25, 2014)

systemd will now relabel /dev after loading the SMACK policy according to SMACK rules.
A new unit file option AppArmoreProfile= has been added to set the AppArmor profile for the processes of a unit.
A new condition check ConditionArchitecture= has been added to conditionalize units based on the system architecture, as reported by uname()'s "machine" field.
systemd-networkd now supports matching on the system virtualization, architecture, kernel command line, host name and machine ID.
logind is now a lot more aggressive when suspending the machine due to a closed laptop lid. Instead of acting only on the lid close action it will continuously watch the lid status and act on it. This is useful for laptops where the power button is on the outside of the chassis so that it can be reached without opening the lid (such as the Lenovo Yoga). On those machines logind will now immediately re-suspend the machine if the power button has been accidentally pressed while the laptop was suspended and in a backpack or similar.
logind will now watch SW_DOCK switches and inhibit reaction to the lid switch if it is pressed. This means that logind will not suspend the machine anymore if the lid is closed and the systemd is docked, if the laptop supports SW_DOCK notifications via the input layer. Note that ACPI docking stations do not generate this currently. Also note that this logic is usually not fully sufficient and Desktop Environments should take a lid switch inhibitor lock when an external display is connected, as systemd will not watch this on its own.
nspawn will now make use of the devices cgroup controller by default, and only permit creation of and access to the usual API device nodes like /dev/null or /dev/random, as well as access to (but not creation of) the pty devices.
We will now ship a default .network file for systemd-networkd that automatically configures DHCP for network interfaces created by nspawn's --network-veth or --network-bridge= switches.
systemd will now understand the usual M, K, G, T suffixes according to SI conventions (i.e. to the base 1000) when referring to throughput and hardware metrics. It will stay with IEC conventions (i.e. to the base 1024) for software metrics, according to what is customary according to Wikipedia. We explicitly document which base applies for each configuration option.
The DeviceAllow= setting in unit files now supports a syntax to whitelist an entire group of devices node majors at once, based on the /proc/devices listing. For example, with the string "char-pts" it is now possible to whitelist all current and future pseudo-TTYs at once.
sd-event learned a new "post" event source. Event sources of this type are triggered by the dispatching of any event source of a type that is not "post". This is useful for implementing clean-up and check event sources that are triggered by other work being done in the program.
systemd-networkd is no longer statically enabled, but uses the usual [Install] sections so that it can be enabled/disabled using systemctl. It still is enabled by default however.
When creating a veth interface pair with systemd-nspawn the host side will now be prefixed with "vb-" if --network-bridge= is used, and with "ve-" if --network-veth is used. This way it is easy to distinguish these cases on the host, for example to apply different configuration to them with systemd-networkd.
The compatibility libraries for libsystemd-journal.so, libsystem-id128.so, libsystemd-login.so and libsystemd-daemon.so do not make use of IFUNC anymore. Instead we now build libsystemd.so multiple times under these alternative names. This means that the footprint is drastically increased, but given that these are transitional compatibility libraries this shouldn't matter much. This change has been made necessary to support the ARM platform for these compatibility libraries, as the ARM toolchain isn't really at the same level as the toolchain for other architectures like x86 and does not support IFUNC. Please make sure to use --enable-compat-libs only during a transitional period!

New in systemd 209 (Feb 20, 2014)

A new component "systemd-networkd" has been added that can be used to configure local network interfaces statically or via DHCP. It is capable of bringing up bridges, VLANs, and bonding. Currently, no hook-ups for interactive network configuration are provided. Use this for your initrd, container, embedded, or server setup if you need a simple, yet powerful, network configuration solution. This configuration subsystem is quite nifty, as it allows wildcard hotplug matching in interfaces. For example, with a single configuration snippet, you can configure that all Ethernet interfaces showing up are automatically added to a bridge, or similar. It supports link-sensing and more.
A new tool "systemd-socket-proxyd" has been added which can act as a bidirectional proxy for TCP sockets. This is useful for adding socket activation support to services that do not actually support socket activation, including virtual machines and the like.
Add a new tool to save/restore rfkill state on shutdown/boot.
Save/restore state of keyboard backlights in addition to display backlights on shutdown/boot.
udev learned a new SECLABEL{} construct to label device nodes with a specific security label when they appear. For now, only SECLABEL{selinux} is supported, but the syntax is prepared for additional security frameworks.
udev gained a new scheme to configure link-level attributes from files in /etc/systemd/network/*.link. These files can match against MAC address, device path, driver name and type, and will apply attributes like the naming policy, link speed, MTU, duplex settings, Wake-on-LAN settings, MAC address, MAC address assignment policy (randomized, ...).
When the User= switch is used in a unit file, also initialize $SHELL= based on the user database entry.
systemd no longer depends on libdbus. All communication is now done with sd-bus, systemd's low-level bus library implementation.
kdbus support has been added to PID 1 itself. When kdbus is enabled, this causes PID 1 to set up the system bus and enable support for a new ".busname" unit type that encapsulates bus name activation on kdbus. It works a little bit like ".socket" units, except for bus names. A new generator has been added that converts classic dbus1 service activation files automatically into native systemd .busname and .service units.
sd-bus: add a light-weight vtable implementation that allows defining objects on the bus with a simple static const vtable array of its methods, signals and properties.
systemd will not generate or install static dbus introspection data anymore to /usr/share/dbus-1/interfaces, as the precise format of these files is unclear, and nothing makes use of it.
A proxy daemon is now provided to proxy clients connecting via classic D-Bus AF_UNIX sockets to kdbus, to provide full compatibility with classic D-Bus.
A bus driver implementation has been added that supports the classic D-Bus bus driver calls on kdbus, also for compatibility purposes.
A new API "sd-event.h" has been added that implements a minimal event loop API built around epoll. It provides a couple of features that direct epoll usage is lacking: prioritization of events, scales to large numbers of timer events, per-event timer slack (accuracy), system-wide coalescing of timer events, exit handlers, watchdog supervision support using systemd's sd_notify() API, child process handling.
A new API "sd-rntl.h" has been added that provides an API around the route netlink interface of the kernel, similar in style to "sd-bus.h".
A new API "sd-dhcp-client.h" has been added that provides a small DHCPv4 client-side implementation. This is used by "systemd-networkd".
There is a new kernel command line option "systemd.restore_state=0|1". When set to "0", none of the systemd tools will restore saved runtime state to hardware devices. More specifically, the rfkill and backlight states are not restored.
The FsckPassNo= compatibility option in mount/service units has been removed. The fstab generator will now add the necessary dependencies automatically, and does not require PID1's support for that anymore.
journalctl gained a new switch, --list-boots, that lists recent boots with their times and boot IDs.
The various tools like systemctl, loginctl, timedatectl, busctl, systemd-run, ... have gained a new switch "-M" to connect to a specific, local OS container (as direct connection, without requiring SSH). This works on any container that is registered with machined, such as those created by libvirt-lxc or nspawn.
systemd-run and systemd-analyze also gained support for "-H" to connect to remote hosts via SSH. This is particularly useful for systemd-run because it enables queuing of jobs onto remote systems.
machinectl gained a new command "login" to open a getty login in any local container. This works with any container that is registered with machined (such as those created by libvirt-lxc or nspawn), and which runs systemd inside.
machinectl gained a new "reboot" command that may be used to trigger a reboot on a specific container that is registered with machined. This works on any container that runs an init system of some kind.
systemctl gained a new "list-timers" command to print a nice listing of installed timer units with the times they elapse next.
Alternative reboot() parameters may now be specified on the "systemctl reboot" command line and are passed to the reboot() system call.
systemctl gained a new --job-mode= switch to configure the mode to queue a job with. This is a more generic version of --fail, --irreversible, and --ignore-dependencies, which are still available but not advertised anymore.
/etc/systemd/system.conf gained new settings to configure various default timeouts of units, as well as the default start limit interval and burst. These may still be overridden within each Unit.
PID1 will now export on the bus profile data of the security policy upload process (such as the SELinux policy upload to the kernel).
journald: when forwarding logs to the console, include timestamps (following the setting in /sys/module/printk/parameters/time).
OnCalendar= in timer units now understands the special strings "yearly" and "annually". (Both are equivalent)
The accuracy of timer units is now configurable with the new AccuracySec= setting. It defaults to 1min.
A new dependency type JoinsNamespaceOf= has been added that allows running two services within the same /tmp and network namespace, if PrivateNetwork= or PrivateTmp= are used.
A new command "cat" has been added to systemctl. It outputs the original unit file of a unit, and concatenates the contents of additional "drop-in" unit file snippets, so that the full configuration is shown.
systemctl now supports globbing on the various "list-xyz" commands, like "list-units" or "list-sockets", as well as on those commands which take multiple unit names.
journalctl's --unit= switch gained support for globbing.
All systemd daemons now make use of the watchdog logic so that systemd automatically notices when they hang.
If the $container_ttys environment variable is set, getty-generator will automatically spawn a getty for each listed tty. This is useful for container managers to request login gettys to be spawned on as many ttys as needed.
%h, %s, %U specifier support is not available anymore when used in unit files for PID 1. This is because NSS calls are not safe from PID 1. They stay available for --user instances of systemd, and as special case for the root user.
loginctl gained a new "--no-legend" switch to turn off output of the legend text.
The "sd-login.h" API gained three new calls: sd_session_is_remote(), sd_session_get_remote_user(), sd_session_get_remote_host() to query information about remote sessions.
The udev hardware database now also carries vendor/product information of SDIO devices.
The "sd-daemon.h" API gained a new sd_watchdog_enabled() to determine whether watchdog notifications are requested by the system manager.
Socket-activated per-connection services now include a short description of the connection parameters in the description.
tmpfiles gained a new "--boot" option. When this is not used, only lines where the command character is not suffixed with "!" are executed. When this option is specified, those options are executed too. This partitions tmpfiles directives into those that can be safely executed at any time, and those which should be run only at boot (for example, a line that creates /run/nologin).
A new API "sd-resolve.h" has been added which provides a simple asynchronous wrapper around glibc NSS host name resolution calls, such as getaddrinfo(). In contrast to glibc's getaddrinfo_a(), it does not use signals. In contrast to most other asynchronous name resolution libraries, this one does not reimplement DNS, but reuses NSS, so that alternate host name resolution systems continue to work, such as mDNS, LDAP, etc. This API is based on libasyncns, but it has been cleaned up for inclusion in systemd.
The APIs "sd-journal.h", "sd-login.h", "sd-id128.h" are no longer found in individual libraries libsystemd-journal.so, libsystemd-login.so, libsystemd-id128.so. Instead, we have merged them into a single library, libsystemd.so, which provides all symbols. The reason for this is cyclic dependencies, as these libraries tend to use each other's symbols. So far, we've managed to workaround that by linking a copy of a good part of our code into each of these libraries again and again, which, however, makes certain things hard to do, like sharing static variables. Also, it substantially increases footprint. With this change, there is only one library for the basic APIs systemd provides. Also, "sd-bus.h", "sd-memfd.h", "sd-event.h", "sd-rtnl.h", "sd-resolve.h", "sd-utf8.h" are found in this library as well, however are subject to the --enable-kdbus switch (see below). Note that "sd-dhcp-client.h" and "sd-daemon.h" are not part of this library (the former because it only consumes, never provides, services of/to other APIs, and the latter because it is completely standalone). To make the transition easy from the separate libraries to the unified one, we provide the --enable-compat-libs compile-time switch which will generate stub libraries that are compatible with the old ones but redirect all calls to the new one.
All of the kdbus logic and the new APIs "sd-bus.h", "sd-memfd.h", "sd-event.h", "sd-rtnl.h", "sd-resolve.h", and "sd-utf8.h" are compile-time optional via the "--enable-kdbus" switch, and they are not compiled in by default. To make use of kdbus, you have to explicitly enable the switch. Note however, that neither the kernel nor the userspace API for all of this is considered stable yet. We want to maintain the freedom to still change the APIs for now. By specifying this build-time switch, you acknowledge that you are aware of the instability of the current APIs.
Also, note that while kdbus is pretty much complete, it lacks one thing: proper policy support. This means you can build a fully working system with all features; however, it will be highly insecure. Policy support will be added in one of the next releases, at the same time that we will declare the APIs stable.
When the kernel command-line argument "kdbus" is specified, systemd will automatically load the kdbus.ko kernel module. At this stage of development, it is only useful for testing kdbus and should not be used in production. Note: if "--enable-kdbus" is specified, and the kdbus.ko kernel module is available, and "kdbus" is added to the kernel command line, the entire system runs with kdbus instead of dbus-daemon, with the above mentioned problem of missing the system policy enforcement. Also a future version of kdbus.ko or a newer systemd will not be compatible with each other, and will unlikely be able to boot the machine if only one of them is updated.
systemctl gained a new "import-environment" command which uploads the caller's environment (or parts thereof) into the service manager so that it is inherited by services started by the manager. This is useful to upload variables like $DISPLAY into the user service manager.
A new PrivateDevices= switch has been added to service units which allows running a service with a namespaced /dev directory that does not contain any device nodes for physical devices. More specifically, it only includes devices such as /dev/null, /dev/urandom, and /dev/zero which are API entry points.
logind has been extended to support behaviour like VT switching on seats that do not support a VT. This makes multi-session available on seats that are not the first seat (seat0), and on systems where kernel support for VTs has been disabled at compile-time.
If a process holds a delay lock for system sleep or shutdown and fails to release it in time, we will now log its identity. This makes it easier to identify processes that cause slow suspends or power-offs.
When parsing /etc/crypttab, support for a new key-slot= option as supported by Debian is added. It allows indicating which LUKS slot to use on disk, speeding up key loading.
The sd_journald_sendv() API call has been checked and officially declared to be async-signal-safe so that it may be invoked from signal handlers for logging purposes.
Boot-time status output is now enabled automatically after a short timeout if boot does not progress, in order to give the user an indication what she or he is waiting for.
The boot-time output has been improved to show how much time remains until jobs expire.
The KillMode= switch in service units gained a new possible value "mixed". If set, and the unit is shut down, then the initial SIGTERM signal is sent only to the main daemon process, while the following SIGKILL signal is sent to all remaining processes of the service.
When a scope unit is registered, a new property "Controller" may be set. If set to a valid bus name, systemd will send a RequestStop() signal to this name when it would like to shut down the scope. This may be used to hook manager logic into the shutdown logic of scope units. Also, scope units may now be put in a special "abandoned" state, in which case the manager process which created them takes no further responsibilities for it.
When reading unit files, systemd will now verify the access mode of these files, and warn about certain suspicious combinations. This has been added to make it easier to track down packaging bugs where unit files are marked executable or world-writable.
systemd-nspawn gained a new "--setenv=" switch to set container-wide environment variables. The similar option in systemd-activate was renamed from "--environment=" to "--setenv=" for consistency.
systemd-nspawn has been updated to create a new kdbus domain for each container that is invoked, thus allowing each container to have its own set of system and user buses, independent of the host.
systemd-nspawn gained a new --drop-capability= switch to run the container with less capabilities than the default. Both --drop-capability= and --capability= now take the special string "all" for dropping or keeping all capabilities.
systemd-nspawn gained new switches for executing containers with specific SELinux labels set.
systemd-nspawn gained a new --quiet switch to not generate any additional output but the container's own console output.
systemd-nspawn gained a new --share-system switch to run a container without PID namespacing enabled.
systemd-nspawn gained a new --register= switch to control whether the container is registered with systemd-machined or not. This is useful for containers that do not run full OS images, but only specific apps.
systemd-nspawn gained a new --keep-unit which may be used when invoked as the only program from a service unit, and results in registration of the unit service itself in systemd-machined, instead of a newly opened scope unit.
systemd-nspawn gained a new --network-interface= switch for moving arbitrary interfaces to the container. The new --network-veth switch creates a virtual Ethernet connection between host and container. The new --network-bridge= switch then allows assigning the host side of this virtual Ethernet connection to a bridge device.
systemd-nspawn gained a new --personality= switch for setting the kernel personality for the container. This is useful when running a 32bit container on a 64bit host. A similar option Personality= is now also available in service units.
logind will now also track a "Desktop" identifier for each session which encodes the desktop environment of it. This is useful for desktop environments that want to identify multiple running sessions of itself easily.
A new SELinuxContext= setting for service units has been added that allows setting a specific SELinux execution context for a service.
Most systemd client tools will now honour $SYSTEMD_LESS for settings of the "less" pager. By default, these tools will override $LESS to allow certain operations to work, such as jump-to-the-end. With $SYSTEMD_LESS, it is possible to influence this logic.
systemd's "seccomp" hook-up has been changed to make use of the libseccomp library instead of using its own implementation. This has benefits for portability among other things.
For usage together with SystemCallFilter=, a new SystemCallErrorNumber= setting has been introduced that allows configuration of a system error number to return on filtered system calls, instead of immediately killing the process. Also, SystemCallArchitectures= has been added to limit access to system calls of a particular architecture (in order to turn off support for unused secondary architectures). There is also a global SystemCallArchitectures= setting in system.conf now to turn off support for non-native system calls system-wide.

New in systemd 208 (Oct 2, 2013)

New in systemd 207 (Sep 13, 2013)

The Restart= option for services now understands a new on-watchdog setting, which will restart the service automatically if the service stops sending out watchdog keep alive messages (as configured with WatchdogSec=).
The getty generator (which is responsible for bringing up a getty on configured serial consoles) will no longer only start a getty on the primary kernel console but on all others, too. This makes the order in which console= is specified on the kernel command line less important.
libsystemd-logind gained a new sd_session_get_vt() call to retrieve the VT number of a session.
If the option "tries=0" is set for an entry of /etc/crypttab its passphrase is queried indefinitely instead of any maximum number of tries.
If a service with a configure PID file terminates its PID file will now be removed automatically if it still exists afterwards. This should put an end to stale PID files.
systemd-run will now also take relative binary path names for execution and no longer insists on absolute paths.
InaccessibleDirectories= and ReadOnlyDirectories= now take paths that are optionally prefixed with "-" to indicate that it should not be considered a failure if they don't exist.
journalctl -o (and similar commands) now understands a new output mode "short-precise", it is similar to "short" but shows timestamps with usec accuracy.
The option "discard" (as known from Debian) is now synonymous to "allow-discards" in /etc/crypttab. In fact, the latter is preferred now (since it is easier to remember and type).
Some licensing clean-ups were made, so that more code is now LGPL-2.1 licensed than before.
A minimal tool to save/restore the display backlight brightness across reboots has been added. It will store the backlight setting as late as possible at shutdown, and restore it as early as possible during reboot.
A logic to automatically discover and enable home and swap partitions on GPT disks has been added. With this in place /etc/fstab becomes optional for many setups as systemd can discover certain partitions located on the root disk automatically. Home partitions are recognized under their GPT type ID 933ac7e12eb44f13b8440e14e2aef915. Swap partitions are recognized under their GPT type ID 0657fd6da4ab43c484e50933c84b4f4f.
systemd will no longer pass any environment from the kernel or initrd to system services. If you want to set an environment for all services, do so via the kernel command line systemd.setenv= assignment.
The systemd-sysctl tool no longer natively reads the file /etc/sysctl.conf. If desired, the file should be symlinked from /etc/sysctl.d/99-sysctl.conf. Apart from providing legacy support by a symlink rather than built-in code, it also makes the otherwise hidden order of application of the different files visible.
The "systemctl set-log-level" and "systemctl dump" commands have been moved to systemd-analyze.
systemd-run learned the new --remain-after-exit switch, which causes the scope unit not to be cleaned up automatically after the process terminated.
tmpfiles learned a new --exclude-prefix= switch to exclude certain paths from operation.
journald will now automatically flush all messages to disk as soon as a message of the log priorities CRIT, ALERT or EMERG is received.

New in systemd 204 (May 11, 2013)

New in systemd 203 (May 7, 2013)

systemd-nspawn will now create /etc/resolv.conf if necessary, before bind-mounting the host's file onto it.
systemd-nspawn will now store meta information about a container on the container's cgroup as extended attribute fields, including the root directory.
The cgroup hierarchy has been reworked in many ways. All objects any of the components systemd creates in the cgroup tree are now suffixed. More specifically, user sessions are now placed in cgroups suffixed with ".session", users in cgroups suffixed with ".user", and nspawn containers in cgroups suffixed with ".nspawn". Furthermore, all cgroup names are now escaped in a simple scheme to avoid collision of userspace object names with kernel filenames. This work is preparation for making these objects relocatable in the cgroup tree, in order to allow easy resource partitioning of these objects without causing naming conflicts.
systemctl list-dependencies gained the new switches --plain, --reverse, --after and --before.
systemd-inhibit now shows the process name of processes that have taken an inhibitor lock.
nss-myhostname will now also resolve "localhost" implicitly. This makes /etc/hosts an optional file and nicely handles that on IPv6 ::1 maps to both "localhost" and the local hostname.
libsystemd-logind.so gained a new call sd_get_machine_names() to enumerate running containers and VMs (currently only supported by very new libvirt and nspawn). sd_login_monitor can now be used to watch VMs/containers coming and going.
.include is not allowed recursively anymore, and only in unit files. Usually it is better to use drop-in snippets in .d/*.conf anyway, as introduced with systemd 198.
systemd-analyze gained a new "critical-chain" command that determines the slowest chain of units run during system boot-up. It is very useful for tracking down where optimizing boot time is the most beneficial.
systemd will no longer allow manipulating service paths in the name=systemd:/system cgroup tree using ControlGroup= in units. (But is still fine with it in all other dirs.)
There's a new systemd-nspawn at .service service file that may be used to easily run nspawn containers as system services. With the container's root directory in /var/lib/container/foobar it is now sufficient to run "systemctl start systemd-nspawn at foobar.service" to boot it.
systemd-cgls gained a new parameter "--machine" to list only the processes within a certain container.
ConditionSecurity= now can check for "apparmor". We still are lacking checks for SMACK and IMA for this condition check though. Patches welcome!
A new configuration file /etc/systemd/sleep.conf has been added that may be used to configure which kernel operation systemd is supposed to execute when "suspend", "hibernate" or "hybrid-sleep" is requested. This makes the new kernel "freeze" state accessible to the user.
ENV{SYSTEMD_WANTS} in udev rules will now implicitly escape the passed argument if applicable.

New in systemd 201 (Apr 9, 2013)

journalctl --update-catalog now understands a new --root= option to operate on catalogs found in a different root directory.
During shutdown after systemd has terminated all running services a final killing loop kills all remaining left-over processes. We will now print the name of these processes when we send SIGKILL to them, since this usually indicates a problem.
If /etc/crypttab refers to password files stored on configured mount points automatic dependencies will now be generated to ensure the specific mount is established first before the key file is attempted to be read.
'systemctl status' will now show information about the network sockets a socket unit is listening on.
'systemctl status' will also shown information about any drop-in configuration file for units. (Drop-In configuration files in this context are files such as /etc/systemd/systemd/foobar.service.d/*.conf)
systemd-cgtop now optionally shows summed up CPU times of cgroups. Press '%' while running cgtop to switch between percentage and absolute mode. This is useful to determine which cgroups use up the most CPU time over the entire runtime of the system. systemd-cgtop has also been updated to be 'pipeable' for processing with further shell tools.
'hostnamectl set-hostname' will now allow setting of FQDN hostnames.
The formatting and parsing of time span values has been changed. The parser now understands fractional expressions such as "5.5h". The formatter will now output fractional expressions for all time spans under 1min, i.e. "5.123456s" rather than "5s 123ms 456us". For time spans under 1s millisecond values are shown, for those under 1ms microsecond values are shown. This should greatly improve all time-related output of systemd.
libsystemd-login and libsystemd-journal gained new functions for querying the poll() events mask and poll() timeout value for integration into arbitrary event loops.
localectl gained the ability to list available X11 keymaps (models, layouts, variants, options).
'systemd-analyze dot' gained the ability to filter for specific units via shell-style globs, to create smaller, more useful graphs. I.e. it's now possible to create simple graphs of all the dependencies between only target units, or of all units that Avahi has dependencies with.

New in systemd 197 (Jan 8, 2013)

Timer units now support calendar time events in addition to monotonic time events. That means you can now trigger a unit based on a calendar time specification such as "Thu,Fri 2013-*-1,5 11:12:13" which refers to 11:12:13 of the first or fifth day of any month of the year 2013, given that it is a thursday or friday. This brings timer event support considerably closer to cron's capabilities. For details on the supported calendar time specification language see systemd.time(7).
udev now supports a number of different naming policies for network interfaces for predictable names, and a combination of these policies is now the default. Please see this wiki document for details:
http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
Auke Kok's bootchart implementation has been added to the systemd tree. It's an optional component that can graph the boot in quite some detail. It's one of the best bootchart implementations around and minimal in its code and dependencies.
nss-myhostname has been integrated into the systemd source tree. nss-myhostname guarantees that the local hostname always stays resolvable via NSS. It has been a weak requirement of systemd-hostnamed since a long time, and since its code is actually trivial we decided to just include it in systemd's source tree. It can be turned off with a configure switch.
The read-ahead logic is now capable of properly detecting whether a btrfs file system is on SSD or rotating media, in order to optimize the read-ahead scheme. Previously, it was only capable of detecting this on traditional file systems such as ext4.
In udev, additional device properties are now read from the IAB in addition to the OUI database. Also, Bluetooth company identities are attached to the devices as well.
In service files %U may be used as specifier that is replaced by the configured user name of the service.
nspawn may now be invoked without a controlling TTY. This makes it suitable for invocation as its own service. This may be used to set up a simple containerized server system using only core OS tools.
systemd and nspawn can now accept socket file descriptors when they are started for socket activation. This enables implementation of socket activated nspawn containers. i.e. think about autospawning an entire OS image when the first SSH or HTTP connection is received. We expect that similar functionality will also be added to libvirt-lxc eventually.
journalctl will now suppress ANSI color codes when presenting log data.systemctl will no longer show control group information for a unit if a the control group is empty anyway.
logind can now automatically suspend/hibernate/shutdown the system on idle.
/etc/machine-info and hostnamed now also expose the chassis type of the system. This can be used to determine whether the local system is a laptop, desktop, handset or tablet. This information may either be configured by the user/vendor or is automatically determined from ACPI and DMI information if possible.
A number of PolicyKit actions are now bound together with "imply" rules. This should simplify creating UIs because many actions will now authenticate similar ones as well.
Unit files learnt a new condition ConditionACPower= which may be used to conditionalize a unit depending on whether an AC power source is connected or not, of whether the system is running on battery power.
systemctl gained a new "is-failed" verb that may be used in shell scripts and suchlike to check whether a specific unit is in the "failed" state.
The EnvironmentFile= setting in unit files now supports file globbing, and can hence be used to easily read a number of environment files at once.
systemd will no longer detect and recognize specific distributions. All distribution-specific #ifdeffery has been removed, systemd is now fully generic and distribution-agnostic. Effectively, not too much is lost as a lot of the code is still accessible via explicit configure switches. However, support for some distribution specific legacy configuration file formats has been dropped. We recommend distributions to simply adopt the configuration files everybody else uses now and convert the old configuration from packaging scripts. Most distributions already did that. If that's not possible or desirable, distributions are welcome to forward port the specific pieces of code locally from the git history.
When logging a message about a unit systemd will now always log the unit name in the message meta data.
localectl will now also discover system locale data that is not stored in locale archives, but directly unpacked.
logind will no longer unconditionally use framebuffer devices as seat masters, i.e. as devices that are required to be existing before a seat is considered preset. Instead, it will now look for all devices that are tagged as "seat-master" in udev. By default framebuffer devices will be marked as such, but depending on local systems other devices might be marked as well. This may be used to integrate graphics cards using closed source drivers (such as NVidia ones) more nicely into logind. Note however, that we recommend using the open source NVidia drivers instead, and no udev rules for the closed-source drivers will be shipped from us upstream.

systemd Changelog

What's new in systemd 242

New in systemd 241 (Feb 14, 2019)

New in systemd 237 (Jan 30, 2018)

New in systemd 236 (Dec 29, 2017)

New in systemd 234 (Jul 13, 2017)

New in systemd 233 (Mar 1, 2017)

New in systemd 232 (Nov 4, 2016)

New in systemd 231 (Jul 25, 2016)

New in systemd 230 (May 22, 2016)

New in systemd 229 (Feb 11, 2016)

New in systemd 228 (Nov 18, 2015)

New in systemd 227 (Oct 8, 2015)

New in systemd 226 (Sep 9, 2015)

New in systemd 225 (Aug 29, 2015)

New in systemd 224 (Aug 5, 2015)

New in systemd 223 (Jul 29, 2015)

New in systemd 221 (Jun 20, 2015)

New in systemd 220 (May 22, 2015)

New in systemd 219 (Feb 17, 2015)

New in systemd 218 (Dec 11, 2014)

New in systemd 217 (Oct 28, 2014)

New in systemd 216 (Aug 20, 2014)

New in systemd 215 (Jul 4, 2014)

New in systemd 213 (May 28, 2014)

New in systemd 212 (Mar 26, 2014)

New in systemd 211 (Mar 12, 2014)

New in systemd 210 (Feb 25, 2014)

New in systemd 209 (Feb 20, 2014)

New in systemd 208 (Oct 2, 2013)

New in systemd 207 (Sep 13, 2013)

New in systemd 204 (May 11, 2013)

New in systemd 203 (May 7, 2013)

New in systemd 201 (Apr 9, 2013)

New in systemd 197 (Jan 8, 2013)

New in systemd 194 (Oct 4, 2012)

New in systemd 193 (Sep 29, 2012)