I was recently doing a Live Migration of some VMs from a Windows Server 2012 Hyper-V cluster to a Windows Server 2012 R2 Hyper-V cluster using Virtual Machine Manager 2012 R2 UR4 and got the following error message:
The VM Server1 cannot be migrated to Host Host1 due to incompatibility issues. Virtual machine migration operation for Server1 failed at migration source Host1.
Resolve the incompatibility issue and try the migration again.
There are other reports that state that they had the same issue. One solution (from Benedict Berger) pointed to a conflict with the Hyper-V virtual switch name of the source and destination host. In my situation, the name of the virtual switch on the destination host was different then the name on the source host.
When doing a live migration between hosts, VMM gives you the possibility to select the VM Network and the virtual switch of the destination host. However, choosing a correct switch did not make a difference.
Renaming Hyper-V Virtual Switches, specially when using Hyper-V Clusters and Logical Switches is not really fun. But there is another option. I created a Private Switch on the destination host using the same switch name as on the source Hyper-V host. After that, I was able to migrate the VM between the 2012 and 2012 R2 Hyper-V cluster.
Once the VM was on the other side, the VM lost it’s network connection. Checking the VM network configuration, every thing was configured correctly and the correct Hyper-V switch was configured on the destination host. To get the VM connected again, I had to select a standard Hyper-V switch for the VM and apply the setting. Checking the VM network configuration again, I saw that the correct logical switch was selected again. Strange… However, the network connectivity of the VM was restored.