[CentOS-virt] XEN and RH 6

Tue Nov 10 14:49:59 UTC 2009
Dennis J. <dennisml at conversis.de>

On 11/10/2009 03:35 PM, Grant McWilliams wrote:
>     Both Novell and Oracle having been deeply involved in Xen lately, both
>     are developing and supporting their own products based on Xen.
>     -- Pasi
>     ___
> I have no problem with a "better" solution than Xen because to be honest
> it's a pain sometimes but at this point virtually all enterprise VM
> deployments are either based on VMware ESX or Xen (Xenserver,
> VirtualIron, Amazon AWS, Oracle, Sun SVM, Redhat and Suse). This tide
> will change as KVM becomes more dominant in the VM space but I don't see
> that happening for a while. I'm also a bit skeptical as to how well a
> fully virtualized system (KVM) will run in comparison to a fully
> paravirtualized system (Xen PV). I have a system with 41 VMs on it and
> I'll be having 2 weeks of planned downtime in the near future. I'd like
> to see how these systems run under KVM.

I've been wondering about the definition of PV in the context of KVM/Xen. 
In the Linux on Linux case for Xen PV practically means that in the HVM 
case I have to access block devices using /dev/hda while in the PV case I 
can use the faster /dev/xvda. When using KVM which apparently only supports 
HVM I can still install a guest using the virtio drivers which seem to do 
the same as the paravirtualized devices on Xen.

So what is the KVM+virtio case if not paravirtualization?