Hyper-V 2012 R2 Cluster - Drain Roles / Fail Roles Back

Hi all,

In the past when I've needed to apply windows updates to my 3 Hyper-V cluster nodes I used to make a note of which VM's were running on each node, then I'd live migrate them to one of the other cluster nodes before pausing the node I need to work on and carry out the updates, once I finished installing the updates I'd then simply resume the node and live migrate the VM's back to their original node.

Having recently upgraded my nodes to Windows 2012 R2 I decided to use the new functionality in Failover Cluster Manager where you can pause & drain a node of its roles, perform the updates/maintenance, and then resume & fail roles back to the node, unfortunately this didn't go as smoothly as I'd hoped, for some reason it seems like the drain/fail back decided to be cumulative rather than one off jobs per-node ... hard to explain, hopefully the following will be clear enough if the formatting survives:

1. Beginning State:

Hyper1     Hyper2     Hyper3

VM01        VM04       VM07
VM02        VM05       VM08
VM03        VM06       VM09

2. Drain Hyper1:

Hyper1     Hyper2     Hyper3

                VM04       VM01
                VM05       VM02
                VM06       VM03
                               VM07
                               VM08
                               VM09

3. Fail Roles Back:

Hyper1     Hyper2     Hyper3

VM01        VM04       VM07
VM02        VM05       VM08
VM03        VM06       VM09

4. Drain Hyper2:

Hyper1     Hyper2     Hyper3

VM01                       VM04
VM02                       VM05
VM03                       VM06
                               VM07
                               VM08
                               VM09

5. Fail Roles Back:

Hyper1     Hyper2     Hyper3

                VM01       VM07
                VM02       VM08
                VM03       VM09
                VM04  
                VM05
                VM06

6. Manually Live Migrate VM's back to correct location:

Hyper1     Hyper2     Hyper3

VM01        VM04       VM07
VM02        VM05       VM08
VM03        VM06       VM09

7. Drain Hyper3:

Hyper1     Hyper2     Hyper3

VM01        VM04
VM02        VM05
VM03        VM06
                VM07
                VM08
                VM09

8. Fail Roles Back:

Hyper1     Hyper2     Hyper3

                               VM01
                               VM02
                               VM03
                               VM04
                               VM05
                               VM06
                               VM07
                               VM08
                               VM09

9. Manually Live Migrate VM's back to correct location:

Hyper1     Hyper2     Hyper3

VM01        VM04       VM07
VM02        VM05       VM08
VM03        VM06       VM09

Step 8 was a rather hairy moment, although I was pleased to see my cluster hardware capacity planning rubber stamped, good to know that if I were ever to loose 2 out of 3 nodes everything would keep ticking over!

So, I'm back to the old ways of doing things for now, has anyone else experienced this strange behaviour?

Thanks in advance,

Ben