[Pacemaker] Live migration question.

[Andrew Beekhof]

On Thu, Jul 12, 2012 at 2:26 PM, David Pendell <lostogre at gmail.com> wrote:
> I have two cluster nodes that have a gigabit network between them for doing
> live migrations of running kvm VMs. If one of the two hosts go off line,
> naturally all of the guests then get restarted on the other host. But when
> the offline host then comes back online, all of the guests that were
> restarted on the "online" host then try to do a live migration. Given that I
> only have one gigabit link for doing the transfers, this creates a log jam.
> The result is that the VMs that timeout then do a "move" or rather shutdown
> VMs to restart them on the newly online node. For my Linux guests, this is
> annoying, but with a Windows VM it is a disaster, locking a very impatient
> dept out of their server for 3-4 minutes. ( One might think that this is a
> miracle, given that before I set up the cluster a server reboot would take
> ten minutes. Sigh. )
>
> I would like to make the migrations sequential so that the Windows VM can
> migrate first, and then the next most important Linux VMs, etc. Is there any
> way to do this?
>
> Beekhof suggested that there were several alternatives and that the mailing
> list would be the best place to ask.

You could try creating an ordering constraint between the two VMs, or
setting batch-limit really small.
I think there were some other options too.