Hahahahaha...Nagios can do MUCH more than just ping machines, my friend. Ping is just the default method by which Nagios checks to see that a host is still UP, or reachable. There are plugins located online, and you need to download, unzip and install those on your Nagios server. Nagios can run SNMP checks, SMTP checks...I've got mine set to monitor binds to other servers and to monitor POP3 on our mail server.
Now, monitoring local checks (disk space, RAM usage, CPU load, etc) on remote hosts is a bit more involved, because you need to have those checks executed locally on each remote host, and then use a daemon such as NRPE or NSCA to get that information back to Nagios. If you have a large number of checks to make, it would be best to use NSCA, where Nagios accepts passive checks but does not actually issue commands to remotely execute these checks. I've only got about 12 or so local checks to execute remotely, so having Nagios instruct NRPE to execute those checks doesn't produce too much wear on my systems. The other option is to write commands with the check_snmp plugin to monitor these services.
Nagios can do quite a bit. Just download what you need and follow the instructions in the documentation provided and you should be mostly set. Of course, we're always here to help...
Edited Tue Jan 10 2006, 04:10AM ]