A: The actual Virtual Hard Disk (VHD) format used by Hyper-V is now a published standard and part of Windows Server 2008 R2, so the actual VHD should be supported for a long time. However, to actually load the entire virtual machine (VM) and its configuration depends on how you save the VM.
If you simply performed a Save action of the VM while it was running, which saves the entire state of the VM, the saved VM wouldn’t be able to be transported to another Hyper-V server nor resumed on any future version of Hyper-V.
Shutting down the VM and storing it would give some greater flexibility in restarting the VM. However, the best option would be to perform an export of the VM to an alternate location. This exports the storage and configuration and should offer the maximum chance of being able to import it in the future, as needed.
To use the VM in the future, you need to maintain a copy of the server OS that you exported the VM from (e.g., Windows Server 2008 R2), as there’s no guarantee future versions of an OS will be able to import a VM exported from an earlier version of Windows.
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