The Sysadmin's Toolbox: sar | Linux Journal
$ sar -s 17:00:00 -e 17:30:00 Linux 2.6.32-29-server (www.example.net) 02/06/2012 _x86_64_ (2 CPU) 05:05:01 PM CPU %user %nice %system %iowait %steal %idle 05:15:01 PM all 4.39 0.00 1.83 0.39 0.00 93.39 05:25:01 PM all 5.76 0.00 all 5.08 0 ......