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.
Platform support 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.
Most Linux distributions provide sar utility through the sysstat package.
Syntax 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.
Example [user@localhost]$ sar # Displays current CPU activity.
Sysstat package Additional to sar command, Linux sysstat package in Debian, RedHat Enterprise Linux and SuSE provides additional reporting tools:
See also atopsar Nmon sag - "system activity graph" command 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
References
Easy system monitoring with SAR (IBM developerWorks) System Activity Reporter (Softpanorama) Article on sar at Computerhope
Footnotes