sar

Additional Notes

sar is a system command used to collect and report historical system activity. It collects and reports system activity data such as CPU, memory, IO, and network usage over time.

sar is part of the sysstat package. Historical data collection must be enabled via sysstat cron jobs or systemd timers.

Syntax

sar [options] [arguments]

Parameters

• options: Flags that change how sar behaves.
• 'interval': Seconds between samples.
• 'count': Number of samples (optional).

Common Options

• -u: CPU usage.
• -r: Memory usage.
• -b: IO statistics.
• -n DEV: Network device statistics.

Examples

sar
sar -u 1 5
sar -r
sar -n DEV 1 3

Practical Notes

sar is part of sysstat and is useful when historical performance data collection is enabled.