Hi, Actually, just a small point of clarification. Guest OSes can know if they're running in a hypervisor in hardware virtualization. If you're using AMD-V, there's an instruction called VMMCALL that allows the guest OS to check to see if it's running under a hypervisor or not. On Intel, the equivalent instruction is VMCALL. This is useful because if it finds that it is running under a hypervisor, it can do things such as ask for more memory if it's running out of memory or ask for more disk space. Here's an article about if: http://developer.amd.com/articles.aspx?id=15&num=3 You can also search google for VMMCALL or VMCALL :) PS. Of course, the guest OS would have to have the ability to do this check. I'm not sure how complicated it would be. Probably a patch to the kernel or something. > On Sat, Oct 07, 2006 at 11:12:00PM +0200, Aryanto Rachmad wrote: > > ----- Original Message ----- > > From: "Daniel P. Berrange" <berrange redhat com> > > To: "Aryanto Rachmad" <aryanto chello at> > > Cc: <fedora-xen redhat com> > > Sent: Saturday, October 07, 2006 10:43 PM > > Subject: Re: What are the minimal required FC6 packages for Dom0? > > > > > > > > > > Fully-virt just lets you run unmodified operating systems (notably Windows, > > > or older versions of Linux for which there is no Xen kernel available). > > > If you only care about running modern Xen enabled Linux kernels then > > > you have on need for fully-virt. As a general rule, if there is a paravirt > > > version of your desired OS available, using that will always be preferrable > > > to fullyvirt. The network & disk I/O is much faster in paravirt, and since > > > the kernel is informed when the hypervisor re-schedules it, it can do much > > > more accurate process accounting in the guest. It is basically impossible > > > to do accurate process scheduling in fully-virt, since the guest kernel > > > has no knowledge of the fact that its running under a hypervisor. > > > > > > > Thanks a lot Dan, > > > > I am actually planning to use Windows XP on one of the guests. So in this case I can not > > do that, cann't I? But on the other hand, I prefer para-virtualised as it has more > > advantages as you explained. > > Yeah, for Windows XP you'll need an Intel-VT or AMD-V capable CPU. > > Regards, > Dan. > -- > |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| > |=- Perl modules: http://search.cpan.org/~danberr/ -=| > |=- Projects: http://freshmeat.net/~danielpb/ -=| > |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=| -- Mathew Brown mathewbrown@xxxxxxxxxxx -- http://www.fastmail.fm - Or how I learned to stop worrying and love email again -- Fedora-xen mailing list Fedora-xen@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-xen