Munin, while a great monitoring tool, can be a little bit of a CPU hog. I had installed it awhile back and looked at the graphs just for fun now and then (I’m lucky, my servers are humming along pretty smoothly), but I started noticing load averages were measurably higher than they were before I was using Munin.
You can’t just stop the munin-node service in some cases; if munin-node graphs are generated by a cron job, you have to stop the cron job too. I had an older CentOS server that required removal of the cron job for the munin user, but on a newer Ubuntu server
all I had to do was stop the munin-node service the munin cron jobs had squirreled themselves away inside /etc/cron.d/munin and /etc/cron.d/munin-node.
See if you can guess what time the munin-node was stopped:
I decided to just run without Munin for awhile; I’ll turn it back on someday if I need it to diagnose something specific, but I don’t see a compelling reason to run it 24×7 just chewing CPU cycles.