Open Stack

On Mon, Aug 10, 2015 at 9:24 AM, Dulko, Michal <michal.dulko at intel.com>
wrote:

> Hi,
>
> In Kilo cycle [1] was merged. It started passing AZ of a booted VM to
> Cinder to make volumes appear in the same AZ as VM. This is certainly a
> good approach, but I wonder how to deal with an use case when administrator
> cares about AZ of a compute node of the VM, but wants to ignore AZ of
> volume. Such case would be when fault tolerance of storage is maintained on
> another level - for example using Ceph replication and failure domains.
>
> Normally I would simply disable AvailabilityZoneFilter in cinder.conf, but
> it turns out cinder-api validates if availability zone is correct [2]. This
> means that if Cinder has no AZs configured all requests from Nova will fail
> on an API level.
>
> Configuring fake AZs in Cinder is also problematic, because AZ cannot be
> configured on a per-backend manner. I can only configure it per c-vol node,
> so I would need N extra nodes running c-vol,  where N is number of AZs to
> achieve that.
>
> Is there any solution to satisfy such use case?
>
> [1] https://review.openstack.org/#/c/157041
> [2]
> https://github.com/openstack/cinder/blob/master/cinder/volume/flows/api/create_volume.py#L279-L282
>
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>

​Seems like we could introduce the capability in cinder to ignore that if
it's desired?  It would probably be worth looking on the Cinder side at
being able to configure multiple AZ's for a volume (perhaps even an
aggregate Zone just for Cinder).  That way we still honor the setting but
provide a way to get around it for those that know what they're doing.

John
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20150810/e3c3cca8/attachment.html>