On Mon, 2009-11-09 at 10:18 +0100, Mathieu Baudier wrote:
I selected one virtual CPU for the XP load...primarily because I want to run a couple more VMs and the guidance was to allocate one real CPU per VM.
My understanding is that Win XP will perform a fundamentally different install depending on whether it detects 1 or many CPU. So if you ever plan to reuse your VM with many CPUs, you should install it with many right away (and follow the tip above: install as Windows Vista, not XP).
I had this problem with a Win XP VM that I installed with pre v3.0 versions of VirtualBox: after VBox introduced SMP I could not use the multi-processor feature since XP had been installed with one processor.
Anyhow, now that I'm using KVM, for my test desktop VMs I tend to allocate a total of CPUs across the VMs higher than the number of my physical CPUs, since they rarely need CPU power at the same time but I want them to be able to run very smoothly if needed.
run a couple more VMs and the guidance was to allocate one real CPU per
Which guidance are you talking about?
In the Red Hat 5 Virtualization documentation it seems to strongly recommends having at least one physical cpu per VM. Since I have a quad core and I want to run the host plus 2-3 VMs, I decided give each VM one virtual cpu. Maybe I was too cautious.
Dave