[ovirt-users] Convert local storage domain to shared

[Christopher Cox]

On 11/29/2017 09:39 AM, Demeter Tibor wrote:
>
> Dear Users,
>
> We have an old ovirt3.5 install with a local and a shared clusters. Meanwhile we
> created a new data center, that based on 4.1 and it use only shared infrastructure.
> I would like to migrate an big VM from the old local datacenter to our new, but
> I don't have enough downtime.
>
> Is it possible to convert the old local storage to shared (by share via NFS) and
> attach that as new storage domain to the new cluster?
> I just want to import VM and copy (while running) with live storage migration
> function.
>
> I know, the official way for move vms between ovirt clusters is the export
> domain, but it has very big disks.
>
> What can I do?

Just my opinion, but if you don't figure out a way to have occasional downtime, 
you'll probably pay the price with unplanned downtime eventually (and it could 
be painful).

Define "large disks"?  Terabytes?

I know for a fact that if you don't have good network segmentation that live 
migrations of large disks can be very problematic.  And I'm not talking about 
what you're wanting to do.  I'm just talking about storage migration.

We successfully migrated hundreds of VMs from a 3.4 to a 3.6 (on new blades and 
storage) last year over time using the NFS export domain method.

If storage is the same across DC's, you might be able to shortcut this with 
minimal downtime, but I'm pretty sure there will be some downtime.

I've seen large storage migrations render entire nodes offline (not nice) due to 
non-isolated paths or QoS.