When I log into Virtualmin Pro and when it automatically monitors the running processes, there is a huge CPU spike, where it can use up to 70% of my server’s CPU time for a while. Why would something ridiculously simple like a process monitor cause such a load?
Try to isolate it down to a particular monitor–I believe I’ve run into this issue on Virtualmin.com with a misbehaving file server and a buggy smb kernel module. The monitor would spawn and the timeout was longer than the time between monitors–so triggers would keep building up. I had the same problem if I tried to work on the broken SMB mounted filesystem from the command line. Anyway, just a theory. I’ve only seen it once, and in a pretty odd environment (our hosting provider gives us access to their NAS for backups, but it’s only accessible via SMB or CIFS–no SSH or secure FTP).
Once we know which monitor is causing the trouble and why we can probably figure out how to make it never happen again via timeouts or error detection in the monitor.