sar (Unix)

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Stable release
sysstat 12.1.1[1] / October 13, 2018; 5 years ago (2018-10-13)
Preview release
sysstat 11.7.4 / June 1, 2018; 5 years ago (2018-06-01) [2]
Written inC
Operating systemAIX, Linux, Solaris, HP-UX
TypeSystem reporting
Called regularly by cron, sadc does the monitoring and stores its measurements to files in the /var/log/sa/ folder. The sar client can be used to explore this data.

System Activity Report (sar) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, interrupts, device load, network and swap space utilization. Sar uses /proc filesystem for gathering information.[3]

Platform support[edit]

Sar was originally developed for the Unix System V operating system; it is available in AIX, HP-UX, Solaris and other System V based operating systems but it is not available for macOS or FreeBSD. Prior to 2013 there was a bsdsar tool, but it is now deprecated.[4]

Most Linux distributions provide sar utility through the sysstat package.


sar [-flags] [ -e time ] [ -f filename ] [-i sec ] [ -s time ]
filename Uses filename as the data source for sar. The default is the current daily data file /var/adm/sa/sadd.
time Selects data up to time. The default is 18:00.
sec Selects data at intervals as close as possible to sec seconds.


[user@localhost]$ sar  # Displays current CPU activity.

Sysstat package[edit]

Additional to sar command, Linux sysstat package in Debian,[5] RedHat Enterprise Linux and SuSE provides additional reporting tools:

See also[edit]

  • atopsar
  • Nmon
  • sag - "system activity graph" command[6]
  • ksar- BSD licensed Java-based application to create graph of all parameters from the data collected by Unix sar utilities.
  • CURT, IBM AIX CPU Usage Reporting Tool
  • isag, tcl based command to plot sar/sysstat data



  1. ^ "Release v12.1.1: Sysstat-12.1.1 · sysstat/Sysstat". GitHub.
  2. ^ "SYSSTAT".
  3. ^ "SYSSTAT".
  4. ^ "FreshPorts -- sysutils/bsdsar: System Activity Reporter for FreeBSD".
  5. ^ "Debian -- Details of package sysstat in sid".
  6. ^ "sag(1)" (PDF). SUNOS Reference Manual. Mountain View, California: Sun Microsystems. 1993-02-24. pp. 1–895. Retrieved 2010-05-04. sag - system activity graph [...] DESCRIPTION sag graphically displays the system activity data stored in a binary data file by a previous sar(1) run.