oracular (1) stress.1.gz

NAME

       stress - tool to impose load on and stress test a computer system

SYNOPSIS

        stress [OPTIONS]

DESCRIPTION

       stress  is  a  tool  that  imposes  a configurable amount of CPU, memory, I/O, or disk stress on a POSIX-
       compliant operating system and reports any errors it detects.

       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.

OPTIONS

       -?, --help
              Show this help statement.

       --version
              Show version statement.

       -v, --verbose
              Be verbose.

       -q, --quiet
              Be quiet.

       -n, --dry-run
              Show what would have been done.

       -t, --timeout <N>
              Timeout after N seconds. This option is ignored by -n.

       --backoff <N>
              Wait for factor of microseconds before starting work.

       -c, --cpu <N>
              Spawn N workers spinning on sqrt().

       -i, --io <N>
              Spawn N workers spinning on sync().

       -m, --vm <N>
              Spawn N workers spinning on malloc()/free().

       --vm-bytes <B>
              Malloc B bytes per vm worker (default is 256MB).

       --vm-stride <B>
              Touch a byte every B bytes (default is 4096).

       --vm-hang <N>
              Sleep N secs before free (default none, 0 is inf).

       --vm-keep
              Redirty memory instead of freeing and reallocating.

       -d, --hdd <N>
              Spawn N workers spinning on write()/unlink().

       --hdd-bytes <B>
              Write  B  bytes  per  hdd  worker (default is 1GB). The file will be created with mkstemp() in the
              current directory.

       Note: Numbers may be suffixed with s,m,h,d,y (time) or B,K,M,G (size).

EXAMPLES

       The simple case is that you just want to bring the system load average up  to  an  arbitrary  value.  The
       following  forks  13  processes,  each  of which spins in a tight loop calculating the sqrt() of a random
       number acquired with rand().

           stress -c 13

       Long options are supported, as well as is making the  output  less  verbose.  The  following  forks  1024
       processes, and only reports error messages if any.

           stress --quiet --cpu 1k

       To see how your system performs when it is I/O bound, use the -i switch. The following forks 4 processes,
       each of which spins in a tight loop calling sync(), which is a system call that flushes memory buffers to
       disk.

           stress -i 4

       Multiple  hogs  may  be  combined  on  the same command line. The following does everything the preceding
       examples did in one command, but also turns up the verbosity level as well as showing how  to  cause  the
       command to self-terminate after 1 minute.

           stress -c 13 -i 4 --verbose --timeout 1m

       You  can  write  a  file  of  arbitrary length to disk. The file is created with mkstemp() in the current
       directory.

           stress -d 1 --hdd-bytes 13

           Large file support is enabled.

           stress -d 1 --hdd-bytes 3G

AUTHOR

       stress was originally developed by Amos Waterland <apw@debian.org> and is maintained by some volunteers.

       Currently, source code and newer versions are available  at  https://github.com/resurrecting-open-source-
       projects/stress