Linux Performance Tuning

Sar & Sysstat: Linux Performance Statistics with Ease

Whenever I perform any type of activity that requires me to look at historical system statistics such as load average, CPU utilization, I/O wait state, or even memory usage; I usually skip the System Monitoring Applications like Nagios or Zenoss and start running the sar command. While I’m not saying that sar completely replaces those tools, I am saying that sar is quick and dirty and if all you want is some raw numbers from a certain time frame; sar is a great tool.