Ceph-backed live migration
OpenStack can support live migration of VMs between compute nodes. Make the necessary configuration changes for ceph-backed volume live migration to work out of the box in deployment scenarios where this configuration is applicable.
Blueprint information
- Status:
- Complete
- Approver:
- None
- Priority:
- Medium
- Drafter:
- subconscious
- Direction:
- Needs approval
- Assignee:
- None
- Definition:
- Approved
- Series goal:
- None
- Implementation:
-
Implemented
- Milestone target:
-
i.0
- Started by
- subconscious
- Completed by
- subconscious
Related branches
Related bugs
Sprints
Whiteboard
There still appears to be a few issues with ceph live migration. Nova has a check for shared storage before doing migration, which breaks the migration process for ceph. Bypassing this by migrating with virsh directly results in permissions issues as virsh wants to copy files from the source hypervisor to the target (disk info and logs). This is the data that exists in /var/lib/
The question that remains is: is shared storage still needed for live migration when using ceph.
Update: shared storage is needed, regardless of the ephemeral storage backend. This is due to metadata files that nova still stores in /var/lib/
libvirt's --copy-storage-all does not appear to be a viable option at this time. This copies all blocks between compute nodes. if using ceph, it *should* just copy the metadata files, which would be minimal in terms of performance overhead.
Work Items
Work items:
nova configuration: DONE
cinder configuration: DONE
is shared storage needed: DONE
nfs live migration: DONE
configure shared storage: DONE
ceph live migration: DONE
