Linux Server Hacks, Volume Two

Hack #74. Profile Your Systems Using /proc

The /proc filesystem holds a wealth of information—and with a little bit of scripting you can use it to create profiles of your servers.

The key to recognizing anomalies on your server is to have a good understanding and knowledge of what things look like when it's healthy. A great place to start hunting for information is the /proc filesystem. This filesystem is a portal into the depths of what the running kernel and the system load look like, and it provides a full profile of the hardware in use on the local system.

When I install a new server, one of the first things I do is take a sort of profile "snapshot," so that I can get a good picture of what the system resources look like on an idle system. I also do this just before and after I install or fire up new software or system services, so I can get a measure of an application's impact on the availability of system resources and so that I have a "cheat sheet" for looking up the system's installed hardware.

The script I use is very rough around the edges and wasn't written for the purpose of working on any machine you might ever run across, but it does work on a good number of Linux servers I've encountered. Let's have a look at each part of the script, along with the output it produces.

The first thing the script does is record the hostname and kernel version information, along with the first several lines of output from the top command, so I can see the load, number of users/processes, ...