Measure twice, crash once (or less)
Having running statistics on your systems is always a good idea.
Since I am a qmail freak, I have been using the venerable qmailmrtg7 for a long while.
In fact since I use my courier pop3/imap server with tcpserver, I can even use qmailmrtg7 to give me stats about POP3 and IMAP, which it susually doesn't.
But... qmailmrtg7 is kinda lame. In part it is lame because it uses mrtg. In part it is lame because it's one opaque thing.
Munin, based on rrdtool is much nicer to look at than mrtg, and has a much more reasonable architecture.
Then, I found qmrtg which is much nicer than qmailmrtg7, and also has a much nicer architecture.
So, why not make a qmunin based on qmrtg which will marry them?
Well, that's an idea.
It's not even very hard to do :-) I should probably do it and publish it.