Mysterious High Server Loads

My dedicated server hosts a single website. The server load typically stays below 1.0, even during the highest traffic periods. It is below 0.25 most of the time.

Each day at about 5pm and 1am the load stays at high levels for about an hour. Typical loads are in the 3.0-7.0 range during these high load periods. When the high load period is complete, the load drops sharply to under 0.5 and remains there.

If I do a "top" or use webmin to look at the processes, nothing is using a large portion of the CPU or memory. There are no unusual processes running. After the period is complete, it appears that the same processes are running as during the high load period. It is almost as if a hidden process is using the server load that does not show up in "top" or webmin.

Does anybody have any ideas about what is causing the server load or how to debug this problem?

 

 

 

 

Top