Q. What are the Hyper-V VM versions?
A. While Hyper-V VM versions have typically not been highly prominent they do exist and the upgrade between Hyper-V VM versions happens automatically as the Hyper-V host is updated. The table below shows the VM versions supported by the various versions of Hyper-V.
|Hyper-V Version/OS||VM Versions Supported|
|Windows Server 2008||1.0|
|Windows Server 2008 SP1||2.0|
|Windows Server 2008 R2||3.0|
|Windows Server 2012||4.0|
|Windows Server 2012 R2||5.0 (4.0 to enable live migration from 2012 and then automatically upgraded to 5.0 after migration)|
|Windows Server vNext||6.0, 5.0, (4.0 to enable live migration from 2012 and then automatically upgraded to 5.0 after migration)|
Note that Windows Server vNext supports both 6.0 and 5.0. This is because 6.0 uses a new binary-based VM configuration format (VMCX). However, you can also continue to use the XML based 5.0 format if you need continued compatibility with pre-vNext. Also note that vNext supports 4.0 to enable a live migration from a 2012 node. To convert a V5 VM to a V6 VM the Update-VMConfigurationVersion cmdlet.