Attachment info lost after migrating a in-use volume

[Lisa Li]

In master branch 2016/8/18,

Create two lvm pools with two backend storages, start volume service.

Create a volume and attach it to an instance.

Migrate the volume to the other backend.

After migration finishes, the attachment info lost.

Before migration,
+--------------------------------------+-----------+------+------+-------------+----------+--------------------------------------+
| ID | Status | Name | Size | Volume Type | Bootable | Attached to |
+--------------------------------------+-----------+------+------+-------------+----------+--------------------------------------+
| b6273fdd-c9ad-4be7-a48a-81d0894df57b | in-use | - | 1 | tet | false | 0dd4615d-b144-47ff-8540-855849e58b2b |

After migration:

\+--------------------------------------+--------+------+------+-------------+----------+--------------------------------------+
| ID | Status | Name | Size | Volume Type | Bootable | Attached to |
+--------------------------------------+--------+------+------+-------------+----------+--------------------------------------+
| b6273fdd-c9ad-4be7-a48a-81d0894df57b | in-use | - | 1 | tet | false | |

And it leads following failure when detaching the volume:

nova volume-detach 0dd4615d-b144-47ff-8540-855849e58b2b b6273fdd-c9ad-4be7-a48a-81d0894df57b
ERROR (BadRequest): Invalid volume: Volume must be attached in order to detach. (HTTP 400) (Request-ID: req-6a666b79-f311-4ece-b716-21de0dd04153)

[Lisa Li (lisali)]

The problem is that in Nova, it detaches the old volume, and attaches the new volume.

https://github.com/openstack/nova/blob/master/nova/compute/api.py#L3296-L3299

But later in cinder, it changes the new volume id with old volume id.

[Lisa Li (lisali)]

Please ignore the above comments.
Real problem exists in migrate_volume_completion

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/356992

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/356992
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=7a8daa5c61cb7b8349bfb12e20304084e0118309
Submitter: Jenkins
Branch: master

commit 7a8daa5c61cb7b8349bfb12e20304084e0118309
Author: lisali <email address hidden>
Date: Thu Aug 18 15:48:01 2016 +0800

    Attachment lost after migrating in-use volume

    Without proper refresh, attachment info are lost after
    migrating in-use volumes. This is to fix the problem.

    Change-Id: I31012a1871b85e038e6595097ad25224488d72a1
    Closes-bug: #1614371

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/cinder 9.0.0.0b3 development milestone.