Ronski
Contributor
Contributor

Very high host CPU usage - am I missing anything here?

Hi,

I have very high CPU usage on a stand-alone ESXI 5.5u3 host, which is usually running 3 guests (I've shutdown the least important one so only 2 are running at the moment):

host.png

Hardware looks OK, and no changes were made in the last few weeks.

Any suggestions?...

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7 Replies
Marmotte94
Enthusiast
Enthusiast

Hello,

Your VM cause a performance problem on your ESXi host. How many vCPU have you got for each VM ?

Can you decrease vCPU for your VMs ?

Thanks,

Olivier.

Please, visit my blog http://www.purplescreen.eu/
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hussainbte
Expert
Expert

The Physical server ESXi looks like having a Quad core CPU with Hyper threading enabled.

There are 2 VMs with total 8 vCPUs.

So the vCPU to pCPU ratio is 1:2.

having 2 virtual CPUs per physical core is not bad.

But looking at your % RDY values, it seems the VMs placed on the host are very CPU intense.

there is nothing being missed here.

You will have to look for increasing physical CPU resources or decrease the workload.

I am sure the VM performance is also badly affected

If you found my answers useful please consider marking them as Correct OR Helpful Regards, Hussain https://virtualcubes.wordpress.com/
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Ronski
Contributor
Contributor

Hi,

%RDY is high, but %USED is 14% for one vm and 12% for the other one - where is the rest?... or am I reading it wrong?

This issue happened overnight, it worked flawlessly for 2 years, with 3 vm's and lots of Mhz to spare.

EDIT:

The vm's are not using much of the host resources, it's host/user and host that does:

Capture.PNG

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Marmotte94
Enthusiast
Enthusiast

hello,

So you don't need more than 2 vCPU for each VM. I recommend to change your setting.

Thank you,

Please, visit my blog http://www.purplescreen.eu/
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hussainbte
Expert
Expert

You can set Each VM to use 2 CPU and try and disable hyperthreading on the ESXi.

If you found my answers useful please consider marking them as Correct OR Helpful Regards, Hussain https://virtualcubes.wordpress.com/
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Ronski
Contributor
Contributor

Guys, please look at the screenshot on my first post in this thread - I am no VMware expert, but if one vm is using 14% and the other 12%, and the entire host is at 100% usage - doesn't it mean that a task/process is running on the host itself, consuming every free MHz? I have shutdown one of the vm's, the other one which I cannot shut down at the moment is consuming 10%, but the host is still at 100%.

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Ronski
Contributor
Contributor

Update: upgraded to ESXi v6.0, problem persists... Smiley Sad

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