Hello everyone, I was wondering if there is any way to debug a high CPU usage after a reboot has occurred. The issue was that I was unable to SSH (or even ping the server) and I forced a reboot from provider's web interface. Ex-post is there any way to check what was causing the high CPU usage? What to look for in logs? Is there any way to narrow it down to certain user or process? I personally suspect that it was either something that sent the mail antivirus into a loop or that one of the websites is infected with something and was running a crypto miner or something... Thank you all for any input. Btw the server is running Debian 8 with ISPConfig.