[Users] Disk Migration

[Dan Kenigsberg]

On Thu, Feb 27, 2014 at 09:12:26AM +0100, Michal Skrivanek wrote:
> 
> On Feb 27, 2014, at 08:15 , Nir Soffer <nsoffer at redhat.com> wrote:
> 
> > ----- Original Message -----
> >> From: "Dafna Ron" <dron at redhat.com>
> >> To: "Maurice James" <midnightsteel at msn.com>
> >> Cc: "Ofer Blaut" <oblaut at redhat.com>, users at ovirt.org
> >> Sent: Wednesday, February 26, 2014 7:34:11 PM
> >> Subject: Re: [Users] Disk Migration
> >> 
> >> On 02/26/2014 05:24 PM, Maurice James wrote:
> >>> I have a specific interface set up for migrations. Why do disk
> >>> migrations not use the interface that I have set for migrations? Is
> >>> that by design? Shouldnt it use the interfaces that I have set aside
> >>> for migrations? VM migrations work as they should but not disk migrations
> >> 
> >> I don't think that you can configure interface for disk migration.
> >> Disk migration is actually copy of information from the original disk to
> >> a new disk created on a new domain + delete of the original disk once
> >> that is done.
> >> it's not actually a migration and so I am not sure you can actually
> >> configure an interface for that.
> >> adding ofer - perhpas he has a solution or it's possible and I am not
> >> aware of it.
> > 
> > I guess that *not* using the migration network for storage operation is
> > the expected behavior, to make migration faster and safer.
> > 
> > Michal, Dan, can you elaborate on this?
> 
> with storage offloading it's probably not going to be significant, however today it likely is.
> Nir, why would not using migration network make it better? Won't we have the same problem as before without migration network at all, i.e. choking the management channel?
> Should we maybe consider a dedicated "storage" network?

As far as I understand Nir, you are saying the same thing: it's better
to separate management, migration, and storage to separate networks, so
that one does not choke the other.

When we get host network QoS done (hopefully ovirt-3.5) we can do this
quite cheaply, over vlans.

Dan.