[libvirt-users] Hot-migration of OVS Vlan configuration

[Antoine Millet]

Hi list,

I'm using OVS as backend for guest networking on my hypervisors. VLAN
configuration for each interface is specified into the guest XML
definition.

When I need to change VLAN configuration of a running guest, I first
edit the inactive XML to keep the changes for future boots, then I use
ovs-vsctl to instruct the changes on the existing OVS Port.

The problem happen when the guest is migrated to another hypervisor.
The "active" XML is used to instantiate the VM on the destination and
this XML doesn't incorporate the changes made to the inactive one. All
the changes made on source are lost on the running guest at
destination.

I'm looking for a solution to this problem:

- IFAIK, I cannot edit the "active" XML myself other than by using
provided Libvirt API (like attach-device), and such API doesn't exists
for VLANs modification on OVS interface
- I cannot use a migration hook to pass changes made to the inactive
XML into the active one because the inactive XML is not reachable from
the hook
- I found a patch allowing to transport some information attached to an
OVS port during migration[1]. Unfortunately, this patch doesn't
transport the VLAN configuration
- Modification of the active XML during the migration itself is not
desirable because it will complicate the migration process by
requesting an external tool

Did I miss something to achieve VLAN configuration migration? How to
implement that into the Libvirt properly?

Thanks!

Antoine

[1] https://www.redhat.com/archives/libvir-list/2012-September/msg01092
.html
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 220 bytes
Desc: This is a digitally signed message part
URL: <http://listman.redhat.com/archives/libvirt-users/attachments/20170711/4aada441/attachment.sig>