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
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2. A bird’s eye view of oVirt
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3. “Language is the means of
getting an idea from my
brain into yours without
surgery.”
(Mark Amidon)
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6. Live Storage Migration in a Nutshell
Definition
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The capability to move one or more VM Disks from one
storage to another without interrupting the guest
operations
Motivation
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Facilitate storage hardware upgrades
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Assist smarter disk provisioning
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Allow storage re-purposing
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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
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9. Flow Overview 1/4 – Initial State
Volume 1
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10. Flow Overview 2/4 – Live Snapshot
Volume 1
Volume 1
Volume 2
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11. Flow Overview 3/4 – Replica & Copy
Volume 1
Volume 1
Volume 2
Volume 1
Volume 2
Volume 1'
Volume 2'
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12. Flow Overview 4/4 - Completion
Volume 1
Volume 1
Volume 2
Volume 1
Volume 2
Volume 1'
Volume 2'
Volume 1'
Volume 2'
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13. Error Handling
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If any error occurs before the copy/replica is
completed:
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●
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Replication is stopped
The volumes on the destination domain are deleted
If any error occurs after the copy/replica is completed:
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The VM is essentially OK
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Junk on the source domain should be cleaned up
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15. Road Map
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Allow Live Storage Migration of multiple VM disks
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Integrate live merge and don’t keep the snapshot
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Supported in QEMU, requires integration
Snapshot only the migrated disk
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Done in oVirt 3.2
Mainly a UI/management issue
Combine with Live VM Migration
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16. How to get involved?
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Main project site:
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Useful wikis
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http://www.ovirt.org
http://www.ovirt.org/Features/Design/StorageLiveMigration
Mailing Lists:
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users@ovirt.org
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arch@ovirt.org
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engine-devel@ovirt.org
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vdsm-devel@lists.fedorahosted.org
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