Dedicate CPU to virtual machine

[Arkady]

Hi,

I have ESX 3.5 Update 1.

Is it possible to assign certain processor(s) to a virtual machine? And set up a rule that this processor(s) will be used for this machine only.

Thank you in advance.

[glynnd1]

Right click VM -> Edit Settings... -> Recources -> Advanced CPU -> Scheduling Affinity (the terms / titles might be different, as I'm looking at ESX4, but Affinity has been there since 2.x days)

This doesn't quite do what you are asking, it restricts the VM from using any processor except the ones you permit it to, rather then reserving a processor for a particular VMs.

Of course been able to do this, and it been a good idea are very different things...so you might want to explain what it is you are hoping to achieve before you shoot your self in the foot.

[Arkady]

I do not see this option under Advanced CPU - attached the screenshot with settings.

The goal is to dedicate CPU to particular virtual machine, so it will not be shared

[Troy_Clavell]

I would advise against setting CPU affinity, this could starve some of your other VM's of resources that are needed. Also, if you set affinity you cannot vmotion.

If you have vCenter and DRS, it let the cluster balance the load.

[Toenuff · Accepted solution]

If you have DRS configured for fully automated you cannot use processor affinity.

It will make the option disappear in the Infrastructure Client. If you have a standalone esx box or one that has DRS set to manual you should see the option on those VMs.

[Toenuff]

As an alternative to what you are trying to do you may want to try the following:

on the VM set the processor reservation to the speed of a single core. If the vm has two processors set the reservation to 2x the speed.... etc.

That should ensure that the ESX hosts always keep that processing power aside for the VM.

[Arkady]

I agree - valid point.

Thank you