Nagios Support Forum

Today my xi server started showing this for Total Processes check on localhost. Should I be concerned? Should I bump up the thresholds? What's a healthy number of processes for the xi server?

Depending on what you're doing, its varies, 388 isn't an unheard of amount, but it is pretty high. Our benchmark box that is running 843 hosts with 3k+ service checks is sitting at 183, but your particular Nagios instance may vary. First thing I would check would be for zombie processes:

ps aux | grep " Z. "

(Note the whitespace)

If you have a lot of these, then this is probably your problem, you'll need to kill them yourself, this can be time-consuming, but there are lots of resources on the internet that show you how automate the zombie killing. Good hunting!

0 zombie processes. We have 571 hosts and 2720 active checks. Is there anything else I should look for?

If it sits at 388 and doesn't grow with indepent of your host additions, then its probably fine. The types of check you're running my require more processes the ones I'm running. However, if it keeps growing for no apparent reason, then it should be a cause for concern.