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I have enabled cpu virtualization on my gigabyte ga-ma770t-up3p and have successfully installed ubuntu 11.10 i386 (after amd64 failed to authenticate). I would like to know how I can verify whether or not my cpu virtualization is being used. I see activity on all 4 cores of my phenom II x4 955 black ed. I'm running ubuntu virtual machine in windows 7 pro host.

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You should at least mention what software you are using for virtualization ;-) – jan groth Jan 21 '12 at 7:39
sorry, running vmware player. – Wiser2001 Jan 21 '12 at 10:57

In VMware, that stat you're looking for is CPU READY which is defined as:

the amount of time a VM is READY to RUN but must WAIT for a the right number of cores to become available.

Just because you tell a VM to use N cores doesn't mean it will actually get the opportunity to use them all. If the HV doesn't have CPU time to lend out, all those extra VCPUs stall. You see you can't just have half of the VCPUs actually ready to do work, they ALL must be ready or the entire group stalls. You'll end up with less performance when compared to running a VM with a single CPU.

Adding VCPUs doesn't always make your VM faster, the additional resource demand can actually crowd it out and result in less overall performance. The right way to do this is to start with 1 VCPU and benchmark your application and increase accordingly.

The more VCPUs you allocated, the higher the likely hood that when the HV is busy that you won't receive VCPU time.

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What virtualization software are you running?

For example Microsofts Virtual PC requires hardware acceleration while VirtualBox don't. Generally, if you in "Settings > System > Acceleration" checks [Enable VT-x/AMD-V] and the virtual machine don't crash, it's probably accelerated.

On you can see a typical error when trying to run on a unsupported hardware.

You can also try to disable hardware acceleration in the bios and see if you notice any difference in load on the host (or in the guest) :-)

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That seems like a very roundabout way to test if cpu virtualization is being used. I ran super-pi in virtual ubuntu and my 2nd core was more active but all cores spiked. VMWare was using an average of 24.7% cpu, but dispersed across all four cores. Am I wrong in my assumption that virtualization should reserve one core for a virtual machine? – Wiser2001 Jan 21 '12 at 10:03
That depends on how you have configured VMWare, I'm not used to VMWare since I've only have used Qemu-KVM, MS Virtual PC and VirtualBox - it seems like VMware (ESXi) is load balancing, at least according to – sakjur Jan 21 '12 at 10:35

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