I'm just after a some advice/tips on upgrading our 3 node Hyper-V cluster from 2008R2 to 2012R2.

I have 3 x Dell r710s running Server 2008R2DC. These are clustered and running about 15 VMs (5 on each host). We have 2 Dell Equalogic SANs storing the VM VHDs.

First of all, we plan to just upgrade our host machines to 2012R2 at first and have them running our 2008R2 VMs. I assume Hyper-V on 2012R2 can run VHD (as well as the new VHDX) format and that running 2008R2 VMs / guest OS isn't an issue?

I'm thinking of running in place upgrades on each node for a simpler process. From what I've read and found online, I think the gist of it is that I can shutdown all of our VMs. Disconnect the iSCSI connections on each host and then evict each node from the cluster manager.

Once evicted, I can upgrade the hosts to 2012 R2 and create a new cluster. Will I be able to then reconnect all the iSCSI targets, add the disk to the pool and import the VMs from their previous config files and VHDs (created in 2008R2)?

Can anyone with experience let me know how they did it and what they would recommend to be the easiest and safest way of upgrading 3 x clustered 2008 host machines?

Downtime isn't an issue for us. We can shutdown all VMs during the process if needed. 

Many thanks in advanced.

1 Answer 1


We recently went through the process of upgrading our 8-node 2012 cluster to 2012 R2.

Uptime in our environment was an issue, so we drained one node, evicted it, formatted and installed 2012 R2, created a new cluster, migrated some VM's to it, lather, rinsed and repeated with each of the subsequent hosts. This was a long and tedious process.

The only reason I'm suggesting the following is that downtime isn't an issue, and your VHDs are safely stored on a SAN:

  1. Nuke the cluster by evicting two of the nodes, then destroy the cluster on the third.
  2. Don't do in-place upgrades... format and install 2012 R2 afresh on each of the hosts
  3. Create new Gen2 VM's for each of the VM's that you've had

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