This has been a problem that we've been battling for some weeks. Whenever large files are copied on the server (both with rsync and cp) the server load initially goes up to 6 or 8 and stabilizes. At some point in the copy load will spike out of control to 50, 100, 150, 200+. At this point we usually fully lose control of the server. This is on a dedicated server with 4GB of RAM and our host keeps telling us that the problem is that MySQL is not getting enough RAM. I don't want to believe that we need more RAM when the server is running fine at normal times.
Any ideas on what is going wrong and how to fix it?