No longer able to attach volumes to instances in nova-vol

[John Griffith]

After persistent tgt patch (https://review.openstack.org/#/c/10414/2) we're no longer able to attach volumes to instances in nova. I've tried the in progress root-wrap patch that was thought to have fixed this but the problem remains.

To reproduce:
    Install latest devstack and remove cinder, c-vol, c-api and c-sch from ENABLED_SERVICES.
    Add n-vol back in to ENABLED_SERVICES
    Run stack.sh
    Run exercises/volumes.sh

Same issue is is currently being worked in Cinder, once it's resolved the changes can be ported back to Nova to fix this bug.

[Thierry Carrez (ttx)]

I think that's a duplicate of bug 1030850

[Thierry Carrez (ttx)]

@John: you should check that https://review.openstack.org/#/c/10549/1 fixed it, and port it to Cinder if it did

[John Griffith (john-griffith)]

This was the result of a number of issues in setting up the new tgtadm changes and the settings required in devstack.

A combination of patches resolve this issue:
Nova https://review.openstack.org/#/c/10628/
Nova https://review.openstack.org/#/c/10636/
Devstack https://review.openstack.org/#/c/10467/

The Cinder chande which would've introduced this bug not landed yet, so it's been fixed in the applicable review so 'no bug' there.