Our main world wide web server, www.eskimo.com, went south this evening for a while. This server normally runs around 20% CPU occupancy, and around 10pm or so the CPU went to 100%, and the I/O gradually fell off. It started complaining about NFS problems talking to Eskimo later even though Eskimo was alive and well and other machines that access files via NFS from it were doing fine. I only found the nfs daemons, www, and named in the 'R' run state, and none of them seemed to have accumulated enough CPU time to account for the 100% CPU occupancy. Killed all the apache processes and it remained at 100%, killed the name server and it remained at 100%. At that point I booted the machine (around 11:30pm). I was not able to locate anything in the logs that would indicate the source of the problem. It seems to be running OK after the reboot.