Reviewed: https://review.openstack.org/507202 Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=ea9bf5216be60fb3fa1704cf6257adca4e634cb1 Submitter: Zuul Branch: master
commit ea9bf5216be60fb3fa1704cf6257adca4e634cb1 Author: Matthew Booth <[email protected]> Date: Mon Sep 25 17:32:14 2017 +0100 libvirt: Don't VIR_MIGRATE_NON_SHARED_INC without migrate_disks If we specify block migration, but there are no disks which actually require block migration we call libvirt's migrateToURI3() with VIR_MIGRATE_NON_SHARED_INC in flags and an empty migrate_disks in params. Libvirt interprets this to be the default block migration behaviour of "block migrate all writeable disks". However, migrate_disks may only be empty because we filtered attached volumes out of it, in which case libvirt will block migrate attached volumes. This is a data corruptor. This change addresses the issue at the point we call migrateToURI3(). As we never want the default block migration behaviour, we can safely remove the flag if the list of disks to migrate is empty. Change-Id: I9b545ca8aa6dd7b41ddea2d333190c9fbed19bc1 Resolves-bug: #1719362 ** 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/1719362 Title: libvirt: Data corruptor live migrating BFV instance with config disk Status in OpenStack Compute (nova): Fix Released Bug description: When live migrating a BFV instance with a config disk, the API currently requires block migration to be specified due to the local storage requirement. This doesn't make sense on a number of levels. Before calling migrateToURI3() in this case, the libvirt driver filters out all disks which it shouldn't migrate, which is both of them: the config drive because it's read-only and we already copied it with scp, and the root disk because it's a volume. It calls migrateToURI3() with an empty migrate_disks in params, and VIR_MIGRATE_NON_SHARED_INC in flags (because block-migration). There's a quirk in the behaviour of the libvirt python bindings here: it doesn't distinguish between an empty migrate_disks list, and no migrate_disks list. Both use the default behaviour of "block migrate all writable disks". This will include the attached root volume. As the root volume is simultaneously attached to both ends of the migration, one of which is running guest, this a data corruptor. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1719362/+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
