sar (Unix)

In computing, sar (System Activity Report) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, device load, network. Linux distributions provide sar through the sysstat package.

Syntax

sar [-flags] [ -e time ] [ -f filename ] [-i sec ] [ -s time ]

-f filename Uses filename as the data source for sar. The default is the current daily data file /var/adm/sa/sadd.

-e time Selects data up to time. The default is 18:00.

-i sec Selects data at intervals as close as possible to sec seconds.

Example

user@localhost:$ sar

Displays current CPU activity.

To add hourly and average CPU usage to a logfile:

echo "SAR on the 1/2 hour and average CPU" >> $LOGFILE
sar | head -4 | tail -1 >> $LOGFILE
sar | tail -3 >> $LOGFILE

See also

• sag - "system activity graph" command^[1]
• 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

References

• sar(1) – Solaris 10 User Commands Reference Manual
• Easy system monitoring with SAR (IBM developerWorks)
• System Activity Reporter (Softpanorama)
• Sysstat package homepage
• Article on sar at Computerhope
• Article on Sar at ITWorld (mentions sar's starting on Solaris)

Footnotes

1. "sag(1)" (PDF). SUNOS Reference Manual. Mountain View, California: Sun Microsystems. 1993-02-24. p. 1231. 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.