Hyper-V host server upgrade from Server 2008 R2 Enterprise SP1 to Server 2012 R2 Datacentre

Question

We are about to upgrade our Hyper-V host servers from Server 2008R2 Enterprise SP1 to Server 2012 R2 Datacentre to take advantage of the latest Hyper-V features.
This only concerns the host servers and not the guest VMs running on the hosts (they will be upgraded next year).
This is what is running on our host servers:
Host 1
File,print & issuing CA server
Exchange 2010
SharePoint 2010
Quickbooks server
Domain controller 1
Offline CRL CA
Host 2
SQL 2008
Forefront TMG 2010
Domain Controller 2
Windows 7 client
With this is mind, I have drafted a rough action plan as follows:
Create a list of all file locations for VM memory, snapshots, virtual memory and Hyper-V config files
Document all existing system settings
Gather server information, download drivers, RAID controller and other boot drivers & firmware updates (in case the in-place upgrade fails)
Test all software media
Copy all VMs onto external data storage (NAS drive)
As part of the upgrade process we will redistribute some hard drive space i.e.
expand them to their new sizes and verify the data integrity of copied VMs by powering up each VM in a test environment
Wipe and adjust the sizes of the host partitions to accommodate the expanded VMs
Perform an in-place upgrade to Server 2012 R2 Datacenter
Check EV, services etc
Change the default locations for VM memory, snapshots, virtual memory and Hyper-V config files
Upgrade Anti-virus and other system software
Test the system
Are there any glaring omissions? Does anyone have any tips they can give me?

Answer 1

Hi Marco,
always do a fresh Installation of your hyper-V Hosts, you could end up doing a lot of Troubleshooting with Drivers,Addons etc.. new Installation ist way faster.
Depending if you have a Cluster or Standalone Servers there are different ways to do it.
When you have installed your 2012 R2 Hyper-V Server you just can Import the VMs from the new Location.
As far as i know VMs with snapshots are not supported, so you have to remove them before doing that move and commit the changes to the vhd files, the VM need to be offline on 2008R2 to do that.
You do not Need to Export the VMs on 2008R2, just copy it, normaly you should have all Files of a VM in one Folder.
A working Backup is always your friend on such Tasks.
When the VMs are running on Hyper-V 2012R2 do not forget to Update the Integration Services.
Make Sure your Servers Hardware are still supported with 2012R2, see Server Catalog and Support Matrix of the Vendor.
And last one, where possible and supported convert the VHDs to VHDx Disks, after testing the first boot of the VM.
Udo