My VPS experiences very high CPU and I/O usages, according to a structural pattern. I don't have a clue what to do about it, or even where to look for problems. It's an unmanaged VPS, so I cannot ask my host for help. It seems that every 12 hours there's a major spike, and in between there are minor spikes, but it's seems there is a structural pattern. So I guess there is some automatic periodic service that is the cause. I wonder if anyone can shed some lights on this. I run Centos 6.3 + ASL + Plesk 11.0.9 Here are some pics and logs to show what's going on.