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Re: [OpenStack] Guest OS shows just one CPU core instead of two

 

I had Windows 8 64bit which shows just 1 Virtual Core and 1 Socket in the
task manager->Performance->CPU tab. I then tried Windows Server 2012 which
shows 2 sockets and 2 Virtual Cores for the same flavor. So it must be some
compatibility issue with KVM and certain versions of Windows.

Thanks for the response.

Regards,
Balu

On Tue, Mar 5, 2013 at 6:19 PM, Daniel P. Berrange <berrange@xxxxxxxxxx>wrote:

> On Tue, Mar 05, 2013 at 04:00:06PM +0530, Balamurugan V G wrote:
> > Hi,
> >
> > I am running Folsom 2.2 with a KVM compute node. When I launch a windows
> > instance with flavor that has 2 VCPUs and 2Gb RAM, the guest seems the
> RAM
> > fine but not the 2 CPUs. It reports only one Virtual processor. Whne I
> look
> > at the command line options with which KVM has launched the instance, I
> see
> > that in -smp argument, sockets is set to 2 and core is set to 1. How can
> I
> > get the core to be 2 so that the guest OS can see it?
>
> There's nothing wrong with what the command line set here. It is
> simply configuring 2 vCPUS where each vCPU is represented as a
> separate socket to the guest, rather than what you describe which
> would be 1 socket with dual-cores.
>
> You don't mention what Windows version you are using, but some versions
> are not clever enough to switch between a uniprocessor config and SMP
> config. So if you installed those versions on a 1 CPU guest, then even
> if you later boot the image on 1 CPU guest, it won't see the extra CPUs.
> There are hacks you can do to "upgrade" a windows install from the
> uniprocessor to multiprocessor HAL - see the microsoft kbase for more
> info
>
> Regards,
> Daniel
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