Nova-compute does not clean up Logical Volume on resize/migrate

[Tyler Wilson]

Noticed this starting in RC1 of Havana (Replicated with release build of Havana), with

libvirt_images_type=lvm
libvirt_images_volume_group=hv1_vg
in nova.conf

I am having to manually remove old Logical Volumes after a resize or migrate has completed in the Horizon UI;

Before Resize
[root@hv1 ~]# lvscan
  ACTIVE '/dev/hv1_vg/volume-9714c3de-b255-46c3-bdf6-234b99309d17' [15.00 GiB] inherit
  ACTIVE '/dev/hv1_vg/instance-00000047_disk' [20.00 GiB] inherit

After Resize
[root@hv3 ~]# lvscan
  ACTIVE '/dev/hv3_vg/instance-00000047_disk' [80.00 GiB] inherit

47_disk still exists;
[root@hv1 ~]# lvscan
  ACTIVE '/dev/hv1_vg/volume-9714c3de-b255-46c3-bdf6-234b99309d17' [15.00 GiB] inherit
  ACTIVE '/dev/hv1_vg/instance-00000047_disk' [20.00 GiB] inherit

In addition, if an instance is migrated or re-sized to a Hypervisor with a previous old Logical Volume (with that same instance disk ID) it will simply re-use the existing volume and not upgrade/downgrade the size.

Debug logs of the instance going to HV: http://pastebin.mozilla.org/3287928 and From HV: http://pastebin.mozilla.org/3287949

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/52811

[lirenke (lvhancy)]

What's the consequence about this bug?

[Joe Gordon (jogo)]

patch was abandoned, is this bug still valid. moving to new to be re-triaged.

[Dan Genin (daniel-genin)]

This is essentially a duplicate of https://bugs.launchpad.net/nova/+bug/1270305. The issue is that libvirt does not have code for migrating/resizing logical volumes and does not know it (i.e., does not fail gracefully). I have submitted a fix to raise a not implemented exception https://review.openstack.org/#/c/73387/.

[Tracy Jones (tjones-i)]

shouldn't this be a dup then? or at least assigned to you?

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/73387
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=e24f333cd5d3667a15c36ac502304bfb5a0e21df
Submitter: Jenkins
Branch: master

commit e24f333cd5d3667a15c36ac502304bfb5a0e21df
Author: Daniel Genin <email address hidden>
Date: Mon Jul 28 17:12:40 2014 -0400

    Raises NotImplementedError for LVM migration.

    Currently migration of an LVM backed instance results in a new
    instance being launched on the destination node, but the instance
    disk is neither copied to the destination nor deleted on the
    origin node. The problem is addressed by raising a NotImplementedError.

    Closes-Bug: #1270305
    Closes-Bug: #1245595
    Closes-Bug: #1241866
    Change-Id: I8010230b1aa5ddc322d0c93dd916b7700c25ab81
    DocImpact