Saturday, December 11, 2010

Lookbusy - A simple application for generating synthetic load on a Linux system

During stress tests it is required to make computational resources like memory, disk space and cpu busy. For this one can do cpu intense operations or memory intense operations or disk intensive operations.

In software testing, a system stress test refers to tests that put a greater emphasis on robustness, availability, and error handling under a heavy load, rather than on what would be considered correct behavior under normal circumstances. In particular, the goals of such tests may be to ensure the software does not crash in conditions of insufficient computational resources (such as memory or disk space), unusually high concurrency, or denial of service attacks. - Wikipedia

One can design different tools for this purpose. While browsing last week in my free time I came across this tool on net which is designed exactly for this purpose. It is working perfectly and very easy to use. Thanks to Devin Carraway <> for providing such a great tool. 


  1. Download Tool which is available at:
  2. Extract the tar ball in some directory
  3. cd into the extracted directory
  4. Issue ./configure
  5. Issue make
  6. Issue 'make install'
  7. You are done with the installation and ready to use

yagna@yagna-desktop:~/Desktop/lookbusy-1.3$ ./lookbusy --help

usage: lookbusy [ -h ] [ options ]
General options:
  -h, --help           Commandline help (you're reading it)
  -v, --verbose        Verbose output (may be repeated)
  -q, --quiet          Be quiet, produce output on errors only

CPU usage options:
  -c, --cpu-util=PCT,  Desired utilization of each CPU, in percent (default
      --cpu-util=RANGE   50%).  If 'curve' CPU usage mode is chosen, a range
                         of the form MIN-MAX should be given.
  -n, --ncpus=NUM      Number of CPUs to keep busy (default: autodetected)
  -r, --cpu-mode=MODE  Utilization mode ('fixed' or 'curve', see lookbusy(1))
  -p, --cpu-curve-peak=TIME
                       Offset of peak utilization within curve period, in
                         seconds (append 'm', 'h', 'd' for other units)
  -P, --cpu-curve-period=TIME
                       Duration of utilization curve period, in seconds (append
               'm', 'h', 'd' for other units)

Memory usage options:
  -m, --mem-util=SIZE   Amount of memory to use (in bytes, followed by KB, MB,

                         or GB for other units; see lookbusy(1))

  -M, --mem-sleep=TIME Time to sleep between iterations, in usec (default 1000)

Disk usage options:
  -d, --disk-util=SIZE Size of files to use for disk churn (in bytes,
                         followed by KB, MB, GB or TB for other units)
  -b, --disk-block-size=SIZE
                       Size of blocks to use for I/O (in bytes, followed
                         by KB, MB or GB)
  -D, --disk-sleep=TIME
                       Time to sleep between iterations, in msec (default 100)
  -f, --disk-path=PATH Path to a file/directory to use as a buffer (default
                         /tmp); specify multiple times for additional paths

Increase Memory Utilization by 1GB

lookbusy -m 1GB

You can verify by using either top or dstat(dstat -m).

Increase CPU Utilization to 70%

lookbusy -c 70

You can verify by using either top or dstat(dstat -cp)

1 comment:

  1. Greetings sir,
    Sir, I got some issues with it.
    Can I get your email id to mail you the issue