check_for_export parameter list inconsistency between nova-volume and cinder

[Chetan Kumar]

Live migration in Cinder environment fails due to the issues identified around check_for_export() below:

1. Parameter inconsistency:
check_for_export() method in nova.volume.manager accepts "instance_id" as a parameter, which is inconsistent with "instance_uuid" used in cinder.volume.manager's check_for_export() def.

The parameter should be updated in nova.volume.manager and the corresponding RPC calls to check_for_export() should be updated.

2. RPC call to check_for_export() in Compute Manager should
   be converted to a RestFul API. This will also ensure that volumes present on multiple volume nodes and attached to an instance are discovered during live migration and migrated successfully.

[Thierry Carrez (ttx)]

Might just be caught in the upcoming cinder/n-v sync

[Chetan Kumar (chetan-kumar)]

Fixed. Patch attached

[Tushar Patil (tpatil)]

After applying the above patch, live migration still doesn't in cinder environment due to recent changes done in this commit Id https://github.com/openstack/cinder/commit/1f3c412e19b4120604453094c2583183aaeff116.

RPC call for check_for_export needs to be converted to the api call (in nova.volume.api and nova.volume.cinder.API).

[Vish Ishaya (vishvananda)]

the check_for_export code was actually removed long ago. It must have been readded when the live migration code moved. Live migration should not be checking for export.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/13412

[Vish Ishaya (vishvananda)]

Adding check_for_export to the api seems like overkill since it doesn't really do anything. I just submitted a patch to remove it.

[Tushar Patil (tpatil)]

You are correct, it make sense to skip check_for_export.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: milestone-proposed
Review: https://review.openstack.org/13482

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/13412
Committed: http://github.com/openstack/nova/commit/683d13604103102112565fe5f93f064c5e4cb1f7
Submitter: Jenkins
Branch: master

commit 683d13604103102112565fe5f93f064c5e4cb1f7
Author: Vishvananda Ishaya <email address hidden>
Date: Thu Sep 20 13:46:27 2012 -0700

    Fix live migration when volumes are attached

    There was some safety code in live-migration to make sure volumes
    were exported before trying to live-migrate volumes. This code is
    broken with cinder as it doesn't expose a way to do this. Since the
    code was basically just a safety measure, this just deletes it so
    live migration works again.

    Fixes bug 1050421

    Change-Id: I3ecd58dc2c37eab30ebfa04140475a9198aede67

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/13482
Committed: http://github.com/openstack/nova/commit/72cb463c7c139dc6905566a497325a18c4fff68c
Submitter: Jenkins
Branch: milestone-proposed

commit 72cb463c7c139dc6905566a497325a18c4fff68c
Author: Vishvananda Ishaya <email address hidden>
Date: Thu Sep 20 13:46:27 2012 -0700

    Fix live migration when volumes are attached

    There was some safety code in live-migration to make sure volumes
    were exported before trying to live-migrate volumes. This code is
    broken with cinder as it doesn't expose a way to do this. Since the
    code was basically just a safety measure, this just deletes it so
    live migration works again.

    Fixes bug 1050421

    Change-Id: I3ecd58dc2c37eab30ebfa04140475a9198aede67
    (cherry picked from commit 683d13604103102112565fe5f93f064c5e4cb1f7)