Resize/Migrate with LVM Restores from Image; Does Not Copy Data

[Tyler Wilson]

It seems when using resize with LVM ephemeral storage simply re-loads the base image rather than transferring the LVM data across servers. To test simply load an Image and make some file alterations, then resize and all changes will be lost. I'm not sure if this is working as intended but I'm assuming not; and if not then it is a critical bug resulting in 'libvirt_images_type=lvm' being unusable with resize.

Further testing reveals this happens with Migrations as well leaving me to believe this is NOT working as intended and leaves LVM critically unusable.

[Guangya Liu (Jay Lau) (jay-lau-513)]

We may need to use lvresize when resize a VM based on LVM image.

[Trump.Zhang (zhangleiqiang)]

I find there is another problem when migrate the instance that use lvm as imagebackend:

After resize-confirm of the migrated instance, the original LV will not be destroyed.

[Solly Ross (sross-7)]

Hey, could you just provide a bit of information about which version of OpenStack you're using? It cuts down on reproduction time.

[Dan Genin (daniel-genin)]

There has been at least three other instances of this bug filed:

https://bugs.launchpad.net/nova/+bug/1150479
https://bugs.launchpad.net/nova/+bug/1270305
https://bugs.launchpad.net/nova/+bug/1241866

in roughly chronological order.

[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