Sysstat
sysstat is a collection of command-line system and performance monitoring utilities for variants of the GNU Operating System such as Linux. This suite of programs can help you understand if a server being slow or unresponsive is due to memory constraints, high CPU load, high I/O load and so on and it's also got tools for pin-pointing what process(es) are causing what load. Learning the various tools in the sysstat package can be quite useful.
The Tools[edit]
There is, ironically, no actual sysstat program. The tools in the sysstat package (the package manager will install all of them when you install sysstat) are:
These tools are actually essential to understanding what is really going on behind the scenes on a server (and they are also useful for a heavily loaded personal desktop).
Links[edit]
sysstat's homepage is at sebastien.godard.pagesperso-orange.fr.
