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