I am monitoring our WHM/Cpanel VPS and notice there are a lot of High Loads during the day.
Most of them show up every day at the same time.
The VPS is a 16 CPU system on a hardware node that has several VPS's running. Not sure how much.
Specific those High Loads are occuring every three hours. But some of them seem to be on other times too, but still daily. Seen peaks of 9.00 Loads for almost 10 minutes of time. Sites are very slow and all WHM/Cpanel functions (webmail etc) are extremely slow during the peaks.
We changed some settings in LFD so every Peak of above two will be reported.
Strange thing is that nothing can be seen during the High Loads, no process is showing that is taking the CPU resources. I checked both, during the Peak via SSH shell (using ps, netstat, vmstat, mpstat) and the logs that are sent by LFD.
Also tried to disable crond for some hours, statistics and backups are only scheduled during the night. Even shut-sown Apache during a one of the High Loads. No effect at all.
What can cause those High Loads?
Why isn't there any process showing up that is consuming all those resources?
How to investigate this further?
Any help is appreciated.
Most of them show up every day at the same time.
The VPS is a 16 CPU system on a hardware node that has several VPS's running. Not sure how much.
Specific those High Loads are occuring every three hours. But some of them seem to be on other times too, but still daily. Seen peaks of 9.00 Loads for almost 10 minutes of time. Sites are very slow and all WHM/Cpanel functions (webmail etc) are extremely slow during the peaks.
We changed some settings in LFD so every Peak of above two will be reported.
Strange thing is that nothing can be seen during the High Loads, no process is showing that is taking the CPU resources. I checked both, during the Peak via SSH shell (using ps, netstat, vmstat, mpstat) and the logs that are sent by LFD.
Also tried to disable crond for some hours, statistics and backups are only scheduled during the night. Even shut-sown Apache during a one of the High Loads. No effect at all.
What can cause those High Loads?
Why isn't there any process showing up that is consuming all those resources?
How to investigate this further?
Any help is appreciated.