vCPU Question

[chaffees]

Hello everyone,

I'm trying to figure out what Windows 2003 server guest OS would see in relation to the physical CPU. Will the vCPU be the same as what the physical CPU would be? Thanks your help, I haven't been able to find anything in the documentation.

[sbeaver · Accepted solution]

If I understand your question correctly then the answer is yes the VM will see the type of processor in the host

Steve Beaver

VMware Communities User Moderator

*Virtualization is a journey, not a project.*

[etieseler]

Yes. The VM will see the specs of the Physical CPU. ESX esentially punches a hole in the virtualization layer for the CPU. So the speed, instruction set, steping, cache, etc., of the CPU is seen buy the VM. It is also the limit of the VM. The max 1 vCPU can use is 1 pCPU.

This is the reason that you cannot VMotion a VM accross CPU's that use different instruction sets. The VM started with the CPU it was booted on and expects those instructions in the CPU to be available, if you have another CPU in the cluster that is older and lacks certain instructions then the VM cannot be moved there. You can shutdown and then boot up the VM on the older CPU however.

-Ed