stress For Linux

stress is a simple tool that imposes a configurable amount of CPU, memory, I/O, and disk stress on POSIX-compliant operating systems. stress is written in portable ANSI C and uses the GNU Autotools to compile on most UNIX-like operating systems. It is free software, licensed under the GNU GPL.

stress is not a benchmark. It is a tool used by system administrators to evaluate how well their systems will scale, by kernel programmers to evaluate perceived performance characteristics, and by systems programmers to expose the classes of bugs which only or more frequently manifest themselves when the system is under heavy load.

stress is listed in the GNU Free Software Directory and has an entry on Freshmeat. It is used by the Linux Test Project and is part of a purpose-optimized GNU/Linux distribution called stresslinux. Linux Magazine did a writeup [pdf] about it. Engler's 2004 OSDI paper titled Using Model Checking to Find Serious File System Errors [pdf] references it.

Here is an example invocation: a load average of four is imposed on the system by specifying two CPU-bound processes, one I/O-bound process, and one memory allocator process.

$ stress --cpu 2 --io 1 --vm 1 --vm-bytes 128M --timeout 10s --verbose stress: info: [9372] dispatching hogs: 2 cpu, 1 io, 1 vm, 0 hdd stress: dbug: [9372] (243) using backoff sleep of 12000us stress: dbug: [9372] (262) setting timeout to 10s stress: dbug: [9372] (285) --> hogcpu worker 9373 forked stress: dbug: [9372] (305) --> hogio worker 9374 forked stress: dbug: [9372] (325) --> hogvm worker 9375 forked stress: dbug: [9372] (243) using backoff sleep of 3000us stress: dbug: [9372] (262) setting timeout to 10s stress: dbug: [9372] (285) --> hogcpu worker 9376 forked stress: dbug: [9375] (466) hogvm worker malloced 134217728 bytes stress: dbug: [9372] (382)