[CentOS] Virtualization supporting 1000Mbps nics?

[Nico Kadel-Garcia]

On Mon, Feb 14, 2011 at 2:34 PM, Smithies, Russell
<Russell.Smithies at agresearch.co.nz> wrote:
> I’ve got xen-3.0.3-105.el5_5.5 running on Centos 5.5 and all is running
> smooth but I notice that any VMs running under it only have access to
> Realtek RTL8139C at 100 Mbps nics.

In general, don't bother. Let the virtualization server handle all the
cute features of the network interfaces, because it's going to
*anyway* as part of its role translating the kernel operations of the
virtualized driver into real hardware interactions with the NIC you
actually use.

> We have 4 x 1G nics configured in a port channel so I’d really like to be
> able to give my VMs 1000Mbps nics.

Actually test the performance, and if possible, use a para-virtualized
kernel. You should see surprisingly good performance.

> Does anyone know if this is possible and how to do it?
>
> If not, does KVM support faster nics because at this point it would be
> fairly simple to change.

See above. In reality, I'll be surprised if you don't easily
outperform a physical RealTek device.