Sar commands comes with the sysstat package. Make sure sysstat is installed. If you don’t have sar installed on your system, get it from Sysstat project.

Sar is an excellent monitoring tool that displays performance data of pretty much every resource of the system including CPU, memory, IO, paging, networking, interrupts etc.,

Sar Collects, Reports (displays) and Saves the performance data.

直接使用 sar 命令会报错:

Cannot open /var/log/sa/sa05: No such file or directory

开启 sysstat 服务解决, 参考

/etc/init.d/systat start