[libvirt-users] Using libvirt with a preexisting network infrastructure

[Vegard Vesterheim]

On Fri, 29 Jul 2011 10:15:09 +0100 Tom Hughes <tom at compton.nu> wrote:

> On 29/07/11 10:08, Vegard Vesterheim wrote:
>
>> I have a server running Ubuntu natty (libvirt 0.8.8) with separate
>> ethernet interfaces. I have created an unnumbered bridge for each
>> interface, these are connected to an already established network
>> infrastructure, with preexisting DHCP and DNS services.
>>
>> I would like to handle *establishment* of these bridges outside libvirt
>> (via /etc/network/interfaces), but still have them defined as networks
>> within libvirt. So, libvirt shall not *configure* the bridges, just be
>> aware of their existence and connect each VM to its configured
>> bridge. This way I can use virt-manager/libvirt to connect my virtual
>> hosts to the correct network. The libvirt commands net-start,
>> net-destroy would become no-ops. It seems that libvirt is geared towards
>> handling all network configuration itself, but I do not need help from
>> libvirt for establishing the bridges, DHCP and DNS.
>
> If you want to connect your VMs to existing bridges then just ignore
> all the network stuff in libvirt and tell your VMs to connect to those
> bridges

Yes, this is exactly what I would like to do.

> - virt-manager should offer the bridges as options when you
> create an interface and you just select the one you want.

I do not see my bridges as options in virt-manager, but when configuring
a network device for a VM, I can select "Specify shared device name" and
manually enter the name of an existing bridge device.

It would be nice if virt-manager could present a menu of existing
devices, or alternatively, that one could define a network in libvirt
which simply refers to the preexisting bridge, but this is good enough
for me.  Thanks.

 - Vegard V -