Open Stack

On 1/16/2017 6:57 AM, Yaguang Tang wrote:
> I'd like to see this feature  "*Attach a single volume to multiple
> instances*"
> https://blueprints.launchpad.net/nova/+spec/multi-attach-volume to be
> implmented in Nova side.
>
> This feature has been working for more than two years, but hasn't been
> accepted by upstream...
>

We have weekly meetings between nova and cinder teams about this and 
have been working on it since Mitaka.

The weekly meeting info is here [1].

My recap of the joint nova/cinder session from Barcelona is here [2].

In a nutshell, we realized toward the end of Mitaka that without 
re-architecting a bunch of the API interaction between nova and cinder 
this would be a huge bolt-on to Nova to support volumes being attached 
to multiple instances. We don't want that. Since then the cinder team 
has been working on new APIs for volume attachment CRUD operations in 
cinder v3 which nova would use for the new interaction to support this 
flow, and the state tracking required. The cinder team has landed the 
initial set of APIs on their side in Ocata. We plan on using those in 
Nova in Pike and we'll be discussing this at the upcoming PTG and it 
should be a review priority item for Pike.

[1] http://eavesdrop.openstack.org/#Cinder,_Nova
[2] 
http://lists.openstack.org/pipermail/openstack-dev/2016-November/107078.html

-- 

Thanks,

Matt Riedemann