Why using Virtualization is making system hangs?

[PM]

On Mon, Jan 2, 2012 at 10:04 PM, compdoc <compdoc at hotrodpc.com> wrote:

>> Can one precisely tell me why the system hangs so often while using any
> guest in the host Ubuntu?

> I have never experienced a system hang using qemu-kvm or virtualbox on an
> Ubuntu host. I have linux and Windows guests running 24/7.
>
> Is it the guest that hangs, or the host? Maybe you can describe a bit more
> detail?

I really forgot to add the details, it was just virtual box in Ubuntu
LTS 10.04 (OSE) which is the host and the guest being openSUSE 11.4,
however, the hangings are in the guest (not in the host). But the
hangings means just for some moments the PC is taking any keyboard
input and doing nothing, not responding (like, e.g., opening an
applications in the guest) but this is random (like it sometimes
happens and sometimes not).......