[ovirt-users] Affinity

[Doron Fediuck]

On 05/01/15 10:54, Koen Vanoppen wrote:
> Hi All,
>
> First of all, let me say a Happy New Year with all the best wishes!!
>
> Now, let's get down to business :-).
>
> I would lik eto implement the Affinity option in our datacenter.
> I already activated it, put the 2 vms in it and set in on negative so
> they won't run together on the same hypervisor. Now, the question...
> Is there a way I can force the VM's so they will run on a hypervisor
> that is not in the same datacenter? We have this;
>
> Hyp1 -> Datacenter1
> Hyp2 -> Datacenter2
> Hyp3 -> Datacenter1
> Hyp4 -> Datacenter2
>
> For the moment they run on a different Hypervisor, but they are in the
> same Datacenter. I can manually now move them to the other one, but I
> would like this that oVirt manages this...
> Is this possible...?
>
> Kind regards,
>
> Koen
>
>
Hi Koen.

VMs cannot move between data centers while still running.
Just to provide some basic concepts in terms of hierarchy, we have:

Data-Center1
|
|\ Cluster A
| |
| |\ Host (a)
| |\ Host (b)
|
|\ Cluster B
| |
| |\ Host (c)
| |\ Host (d)
| |\ Host (e)

Data-Center2
|
|\ Cluster A
| |
| |\ Host (f)
|
|\ Cluster B
| |
| |\ Host (g)
| |\ Host (h)
| |\ Host (i)

As you can see, a host may be a part of a single cluster and a VM
will run on one of the hosts. Live migration can be done between
hosts of the same cluster. The only way to move VM between clusters
and DCs are when the VM is down, in a manual way.

So Affinity works in the cluster level, and the rules are valid for a
specific cluster who currently owns the VM.
In your case if Hyp1 and Hyp3 belong to the same cluster, the affinity
rules will apply every time you start or migrate a VM. However, there's
no rule which is valid for Datacenter1 and Datacenter2.

HTH,
Doron
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20150105/76374465/attachment-0001.html>