I have an Ubuntu 16.04 server with ISPConfig 3.1 and many websites installed. For some reason the server started working too much on some processes with high load, and it gets too slow from time to time. I don't know what the running processes associated with this problem are, but it doesn't work well anymore. I want to identify the running processes in order to figure out the solution. Hopefully someone can shed some light. Thanks in advance.