Live Storage Migration in oVirt (Open Storage Meetup May 2013)
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The document discusses live storage migration in oVirt, which allows moving one or more VM disks from one storage to another without interrupting guest operations. This facilitates storage upgrades and smarter disk provisioning. Live storage migration works by taking a live snapshot of the disk, replicating the changes to a new disk on the target storage, and then completing the migration by switching the disk to the target storage and deleting the snapshot. Future work may integrate live merge to avoid keeping snapshots and allow migrating multiple disks or combining with live VM migration.
Live Storage Migration in oVirt (Open Storage Meetup May 2013)
- 1. Live Storage Migration in oVirt Over and Under the Hood Allon Mureinik Team Lead, Cloud Storage, Red Hat May 2013 Allon Mureinik - Live Storage Migration Over and Under Hood 1
- 2. A bird’s eye view of oVirt Allon Mureinik - Live Storage Migration Over and Under Hood 2
- 3. “Language is the means of getting an idea from my brain into yours without surgery.” (Mark Amidon) Allon Mureinik - Live Storage Migration Over and Under Hood 3
- 4. oVirt Architecture Allon Mureinik - Live Storage Migration Over and Under Hood 4
- 5. Live Storage Migration Over the Hood Allon Mureinik - Live Storage Migration Over and Under Hood 5
- 6. Live Storage Migration in a Nutshell Definition ● The capability to move one or more VM Disks from one storage to another without interrupting the guest operations Motivation ● Facilitate storage hardware upgrades ● Assist smarter disk provisioning ● Allow storage re-purposing Allon Mureinik - Live Storage Migration Over and Under Hood 6
- 7. A Picture is Worth 1024 Words Host A Host A VM Virtual Disk Storage A Storage B VM Virtual Disk Storage A Storage B Allon Mureinik - Live Storage Migration Over and Under Hood 7
- 8. Live Storage Migration Under the Hood Allon Mureinik - Live Storage Migration Over and Under Hood 8
- 9. Flow Overview 1/4 – Initial State Volume 1 Allon Mureinik - Live Storage Migration Over and Under Hood 9
- 10. Flow Overview 2/4 – Live Snapshot Volume 1 Volume 1 Volume 2 Allon Mureinik - Live Storage Migration Over and Under Hood 10
- 11. Flow Overview 3/4 – Replica & Copy Volume 1 Volume 1 Volume 2 Volume 1 Volume 2 Volume 1' Volume 2' Allon Mureinik - Live Storage Migration Over and Under Hood 11
- 12. Flow Overview 4/4 - Completion Volume 1 Volume 1 Volume 2 Volume 1 Volume 2 Volume 1' Volume 2' Volume 1' Volume 2' Allon Mureinik - Live Storage Migration Over and Under Hood 12
- 13. Error Handling ● If any error occurs before the copy/replica is completed: ● ● ● Replication is stopped The volumes on the destination domain are deleted If any error occurs after the copy/replica is completed: ● The VM is essentially OK ● Junk on the source domain should be cleaned up Allon Mureinik - Live Storage Migration Over and Under Hood 13
- 14. Looking Forward Allon Mureinik - Live Storage Migration Over and Under Hood 14
- 15. Road Map ● Allow Live Storage Migration of multiple VM disks ● ● Integrate live merge and don’t keep the snapshot ● ● Supported in QEMU, requires integration Snapshot only the migrated disk ● ● Done in oVirt 3.2 Mainly a UI/management issue Combine with Live VM Migration Allon Mureinik - Live Storage Migration Over and Under Hood 15
- 16. How to get involved? ● Main project site: ● ● Useful wikis ● ● http://www.ovirt.org http://www.ovirt.org/Features/Design/StorageLiveMigration Mailing Lists: ● users@ovirt.org ● arch@ovirt.org ● engine-devel@ovirt.org ● vdsm-devel@lists.fedorahosted.org Allon Mureinik - Live Storage Migration Over and Under Hood 16
- 17. Q&A Allon Mureinik - Live Storage Migration Over and Under Hood 17