For the last few days, my VPS is suffering from apparently random times of very high processor load, and I'm at a loss as to their cause.
Normal load is around 0.1, but about 2-3 times a day it goes up to at least 5, often above 20, lasting for 5-30 minutes. The hosting company staff (united-hoster.com) has twice shut down my VPS at those times because the load was too high.
Unfortunately, neither top nor netstat reveals anything insightful, and I don't see any cron jobs scheduled for these times. There sometimes appears to be slightly more apache and qmail activity, but nothing very extraordinary. Bandwidth use is moderate throughout. Here's an example:
hm, could it be a kernel problem? I just saw that people have reported similar problems with other versions of 2.6.9, though on CentOS. (This board doesn't let me post URLs (says I need >=5 posts), so I've seen that on: www dot vbulletin dot com slash forum slash showthread.php?t=171071.)