Sysstat

Sysstat

Used in conjunction with cron to log snapshots of system stats like CPU load. Good for gathering historical stats on servers.

Ubuntu

To enable sysstat logging on Ubuntu do the following:

dpkg-reconfigure sysstat

Choose <Yes> to activate sysstat's cron job.

References

http://abdussamad.com/archives/167-CPU-load-average-history-in-Linux.html