How to fix High CPU Ready %

[fitzie22]

I have 30 vm's running on a 3.5 ud 4 host and they all have cpu ready %'s of less that 2 except one of them that is up over 30. How can I correct this. I am not sure if this is a shares thing or a reservation. any help would be excellent.

[Troy_Clavell]

how many vCPU's does the guest in question have? Do you have any limits set on this guest?

[fitzie22]

there are no limits setup on teh vm and there are 4 vcpu's becasue teh application did not perform with 2. I was against 4 becacue of contention but it was what I had to deal with

[Troy_Clavell]

having 4vCPU's in itself may cause performance issues, but you can try to set the share level to high for that guest. It's a double edge sword, while the 4vCPU guest may perform better with more shares, you could affect the performance of the other guests.

[Linjo]

Depending how many cores you have in each host this is most likely the problem

Giving a lot of VM:s 4 cores you give the ESX Scheduler a tough job trying to fit the VM:s onto the physical cores.

As I see it you have 2 options: increase the number of hosts or reduce the number of vCPU:s in the VM:s.

Best regards,

Linjo

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[khughes]

I agree with everything that has been said here, the one way to get around having to add hosts or reducing the vCPU's is try and balance out the hosts differently. Move some of the VM's with only 1 vCPU's to another host to try and free up some scheduling issues. There is really no way around CPU Ready besides either lessening the resources the virtual machine is using or add resources for the virtual machine to use.

Kyle