In the last two weeks, Peter Zaitsev published a 4-part series on measuring Linux performance on this blog.

His writings cover the 4 main areas where you can spot performance problems on any Linux machine, with practical tips on how to draw the right conclusions. Here are the individual pieces:

Measuring Linux Performance: CPU
Measuring Linux Performance: Disk
Measuring Linux Performance: Memory
Measuring Linux Performance: Network

I found these gave a good overall summary of the things to be on the look-out for whenever you’re troubleshooting slow applications or slow servers.