I hope this isn’t too clueless a question. I’ve been dealing mainly with Nagios .cfg files (not a lot else Nagios-related) for about 3 years now, and have just run into something that makes me wonder more about the app’s methods …
A few days ago I clicked on the “Host Problems” link in the sidebar by mistake, and saw that a monitored server was appearing as “down” on that screen … even though I had not received any email notification from Nagios that it was down. FWIW, it was a 3Par server. Further, the only service this box was configured to have monitored was SSH … which was green and fine.
I’ve been trying to figure out why this box was showing as down and the question that has come back at me is: how does Nagios check this sort of thing?
My problem is that, given there was only one service configured (and it was up) … I don’t know.
Any pointers, even RTFMs, are welcome.