I’ve been asked over and over and over how to upgrade from a Windows Server 2008 R2 Hyper-V cluster to a Windows Server 2012 Hyper-V cluster. You cannot do an in-place upgrade of a cluster. What I’ve said in the past, and it still holds true, is that you can:
- Buy new host hardware, if your old hardware is out of support, build a new cluster, and migrate VMs across (note that W2008 R2 does not support Shared-Nothing Live Migration), maybe using export/import or VMM.
- Drain a host in your W2008R2 cluster of VMs, rebuild it with WS2012, and start a new cluster. Again, you have to migrate VMs over.
The clustering folks have another way of completing the migration in a structured way. I have not talked about it yet because I didn’t see MSFT talk about it publicly, but that changes as of this morning. The Clustering blog has details on how you can use the Cluster Migration Wizard to migrate VMs from one cluster to another.
There is still some downtime to this migration. But that is limited by migrating the LUNs instead of the VHDs using unmask/mask – in other words, there is no time consuming data copy.
Features of the Cluster Migration Wizard include:
- A pre-migration report
- The ability to pre-stage the migration and cut-over during a maintenance window to minimize risk/impact of downtime. The disk and VM configurations are imported in an off state on the new cluster
- A post-migration report
- Power down the VMs on the old cluster
- You de-zone the CSV from the old cluster – to prevent data corruption by the LUN/VM storage being accessed by 2 clusters at once
- Then you zone the CSV for the new cluster
- You power up the VMs on the new cluster
Things might change when we migrate from Windows Server 2012 Hyper-V to Windows Server vNext Hyper-V, thanks to Shared-Nothing Live Migration
Fellow Virtual Machine MVP, Didier Van Hoye, beat me to the punch by 1 minute on this post He also has a series of posts on the topic of cluster migration.