cant live migrate volume backed instances when rbd for Nova is not enabled

[Andrew Woodward]

Unless "Ceph RBD for ephemeral instances" is selected, live migration isn't configured so it's not possible to live migrate a cinder volume backed by Ceph.

Steps to reproduce:
1) Deploy with Ceph enabled for Cinder but not for Nova, with 2 or more compute nodes.
2) Create a volume from an image.
3) Boot an instance from that volume.
4) Live migrate that instance.
Expected result: live migration successful.

[Dmitry Borodaenko (angdraug)]

P.S. Live migration of LVM based Cinder volume backed instance should also work.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/102486

[Sergii Golovatiuk (sgolovatiuk)]

Live Block Migration has been fixed. However, I think we need to add more values to nova.conf

block_migration_flag=VIR_MIGRATE_LIVE,VIR_MIGRATE_TUNNELLED,VIR_MIGRATE_PEER2PEER,VIR_MIGRATE_NON_SHARED_INC,VIR_MIGRATE_UNDEFINE_SOURCE
live_migration_flag=VIR_MIGRATE_UNDEFINE_SOURCE,VIR_MIGRATE_PEER2PEER,VIR_MIGRATE_LIVE

to enable true live migration without pausing instances during the migration.

Currently you can test live migration using this guide

1. Since we don’t distribute openrc, grab it from controller and export variables on compute
2. Make sure nova cli works
nova flavor-list
nova image-list
3. Create instance
nova boot --flavor 1 --image <ID_FROM_IMAGE_LIST> test2
4. Find out the node where instance is launched and export variables from openrc on it
5. Perform migration
nova live-migration --block_migrate test2 node-12
6. Check the status of VM
nova list
7. Check if VM was migrated successfully

[Bogdan Dobrelya (bogdando)]

related ML http://osdir.com/ml/openstack-dev/2014-06/msg01671.html

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/102486
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=ead25e2eb43140c0a12f2cddf7ee0dbbc422550c
Submitter: Jenkins
Branch: master

commit ead25e2eb43140c0a12f2cddf7ee0dbbc422550c
Author: Sergii Golovatiuk <email address hidden>
Date: Wed Jun 25 10:14:59 2014 +0000

    Fix live migration for File/Volume based Instances

    - Open libvirt ports for migration http://wiki.libvirt.org/page/FAQ
    - Add python-novaclient for compute nodes to provide nova CLI
    - Change libvirt_disk_cachemodes to"file=directsync","block=none".

    This allows live block migration, as DirectSync mode is like writethrough, but it bypasses the host page cache.

    Closes-Bug: 1329953
    Change-Id: Ie7cee823fac70f9c2dd46c04f8651cec6bddccc4

[Egor Kotko (ykotko)]

{u'build_id': u'2014-07-03_12-42-15', u'ostf_sha': u'd0fe60e0eba61685008b86d101f459fc2d3bb654', u'build_number': u'89', u'api': u'1.0', u'nailgun_sha': u'5c18e962d85b878e53ff6eb6eeeb14658814c5b8', u'production': u'docker', u'mirantis': u'yes', u'fuelmain_sha': u'1072bc723d14427d5fdc24662ffe1af0641e0d9a', u'astute_sha': u'644d279970df3daa5f5a2d2ccf8b4d22d53386ff', u'release': u'5.0.1', u'fuellib_sha': u'385d713b569bc0633e695b44ff7eedf3417f0575'}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/5.0
Review: https://review.openstack.org/112819

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/112819
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=fa6b19963023b2e8d70f3fba300c75322f7bb476
Submitter: Jenkins
Branch: stable/5.0

commit fa6b19963023b2e8d70f3fba300c75322f7bb476
Author: Sergii Golovatiuk <email address hidden>
Date: Wed Jun 25 10:14:59 2014 +0000

    Fix live migration for File/Volume based Instances

    - Open libvirt ports for migration http://wiki.libvirt.org/page/FAQ
    - Add python-novaclient for compute nodes to provide nova CLI
    - Change libvirt_disk_cachemodes to"file=directsync","block=none".

    This allows live block migration, as DirectSync mode is like writethrough, but it bypasses the host page cache.

    Closes-Bug: 1329953
    Change-Id: Ie7cee823fac70f9c2dd46c04f8651cec6bddccc4