Reviewed: https://review.openstack.org/346263 Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=d7b831e38cbc029b7975d1059ed212762a5f6a5e Submitter: Jenkins Branch: master
commit d7b831e38cbc029b7975d1059ed212762a5f6a5e Author: Chris Friesen <[email protected]> Date: Fri Jul 22 16:33:43 2016 -0600 Fix cold migration with qcow2 ephemeral disks If we have qcow2 ephemeral disks we need to ensure that the backing file gets created on a cold migration. This requires passing in the block_device_info when calling _create_image() so that we can loop over the ephemeral disks. Closes-Bug: #1605720 Co-Authored-By: Feodor Tersin <[email protected]> Change-Id: Ie278bb10e1675ba1d903aaa3c0249be0d1cf147b ** Changed in: nova Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1605720 Title: backing store missing for ephemeral disk on cold migration Status in OpenStack Compute (nova): Fix Released Bug description: I'm on stable/mitaka, but the master code looks similar. I have compute nodes configured to use qcow2 and libvirt. The flavor has an ephemeral disk and a swap disk, with root disk size of "0" for auto-size. I boot an instance with this flavor. When I try to cold-migrate the instance, I get an error: 2016-07-21 23:33:48.561 46340 ERROR nova.compute.manager [instance: 4e52bfd8-0c71-48dc-89fb-6f6b31dc06bb] libvirtError: Cannot access backing file '/etc/nova/instances/_base/ephemeral_1_0706d66' of storage file '/etc/nova/instances/4e52bfd8-0c71-48dc-89fb-6f6b31dc06bb/disk.eph0' (as uid:0, gid:0): No such file or directory The problem seems to be that in nova.virt.libvirt.driver.LibvirtDriver.finish_migration() we call self._create_image(...block_device_info=None...) Down in _create_image() we handle the case of a "disk.local" ephemeral device, but that doesn't help because the device is actually named "disk.eph0". It looks like we then try to loop over any ephemerals in block_device_info, but that's None so we don't handle any of those (which is too bad since it looks like they would be named correctly). The end result is that we have a qcow2 "disk.eph0" image, but with potentially no backing store in <instances_path>/_base. When we tell libvirt to start the instance, this results in the above error. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1605720/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
