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I'm running Ubuntu Linux 12.04.1, with VirtualMin 4.08.gpl GPL and 2 CPU cores.
Pretty much all the time for the last few weeks, it's been running at well above load average of 5, usually up closer to 10, sometimes reaching 20.
Right now, CPU load averages: 9.20 (1 min) 8.20 (5 mins) 7.81 (15 mins)
At the same time, VirtualMin returns:
Virtual Memory: 996 MB total, 15.44 MB used Real Memory: 3.80 GB total, 972.43 MB used Local disk space: 915.94 GB total, 116.03 GB used
Have restarted (
shutdown -rf now) the machine a few times and sure enough sooner or later we're back up with high CPU loads.
htop) returns nothing significant at all running at high CPU - in fact watching it for a few minutes and the highest item would maybe high 3% CPU.
Top returns this also:
Cpu(s): 2.2%us, 1.2%sy, 0.0%ni, 0.0%id, 96.5%wa, 0.0%hi, 0.2%si, 0.0%st
%wa concerns me as it's so high - seems to stay up above 80%. I understand this is % in wait, but not sure what that means in practical terms.
Where can I start to debug this and figure out what's causing the high CPU load?