If you have already an existing Windows Server 2008 R2 Hyper-V cluster and you want to upgrade to Windows Server 2012 you have two options. The first one is by moving all virtual machines via System Center Virtual Machine Manager from the old Cluster into a new cluster. The second way to do it, is to use the Cluster Migration Wizard which is part of Windows Server 2012.
In my case I have two clusters one “old” Windows Server 2008 R2 Hyper-V cluster and my new Windows Server 2012 Hyper-V cluster. Both Clusters are fully configured and both have access to the same disks/LUNs. The disk and all the VMs are running on the old cluster.
On the new cluster you can start the Cluster Migration Wizard.
This will bring up the Cluster Migration Wizard. The wizard will ask you about the old cluster.
The Cluster Migration Wizard will scan the old cluster for CSVs and Cluster roles. You have to select the Cluster Shared Volume you want to migrate to the new cluster. Note: you can only migrate CSVs including all virtual machines running on this CSV and not just single virtual machines. If you want to migrate single virtual machines you could do a Hyper-V Export/Import or using System Center Virtual Machine Manager.
Since the Cluster Migration Wizard detects the roles as Hyper-V virtual machines he also asks for the new Hyper-V Virtual Switch.
You get a quick summary with all the information what the Migration Wizard will do, and you can migrate all roles. This means the Migration Wizard will create all cluster roles on the new cluster but will not take the existing VMs offline the VMs at this point are still running on the old cluster. You also get a Failover Cluster Migration Report at the end.
This report also shows you what’s next:
All the clustered services and applications selected for migration were migrated successfully. You may now take the clustered services and applications offline in your old cluster. Also take offline Cluster Shared Volumes used by any migrated roles, as well as storage pools for virtual disks used by any migrated roles. Then these disks, Cluster Shared Volumes, and clustered services and applications can be brought online in your new cluster.
In the new cluster you can now see the roles which are all turned of because there are still running on the old cluster. And you can also see the CSV which is offline on the new cluster and online on the old cluster.
As already mentioned we had no downtime until now. Now you can go and shutdown all the virtual machines running on your old cluster and take the migrated CSV offline.
Take the CSV offline
On the new cluster bring the CSV online
Bring the virtual machines on the new cluster back online.
And this is more how you can migrate a cluster. Remember there are still some tasks left.
- Upgrade the Integration Components of all the virtual machines to the newest version.
- Convert all VHDs to the new VHDX format to dynamic disks.
- I also recommend that you use CSV Block Cache
There is also a great video from Symon Perriman and Rob Hindman, a Program Manager on the Windows Server Clustering & High-Availability team, in which they explain how you can upgrade to Windows Server 2012 Hyper-V.