Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes. For some functions (most notably the "map" function), you need to have X installed on your server. You do not have to start X though, nagios just needs some of the libraries and fonts. For a useful setup, you will want to have monitoring-plugins installed (nagios-plugins is also an option, but make sure to edit resource.cfg). Check the included 'README.SLACKWARE' file for additional setup instructions. Lots of information is available in the included documentation, and even more can be found on the nagios site and wiki .