sar (Unix)

In computing, sar (system activity monitor) is a Solaris-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 . Default is the current daily data file /var/adm/sa/sadd.

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

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

Example

user@localhost:$ sar

Displays today's CPU activity so far. You must have permission and the information must be present on the computer.

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

References

• 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)