Virtual Machine Manager

VMM 2019 – VM Template deploying random VHDXs

I recently came across a very strange *issue* on my VMM 2019 lab, after creating a new Windows 10 2004 VHDX template, I noticed when attempting to deploy VM’s using this template that I would end up receiving my Windows 10 1909 or Server VHDX, needless to say, I was baffled, I couldn’t see anything wrong my setup whatsoever, I’m not entirely sure if this is a bug or by design, however, it’s something to be aware of as it’s an experience that isn’t particuarly obvious to what the issue is, here’s how to remediate it.

Issue

As described above, I recently created a new Windows 10 2004 VHDX template and after deploying this VM template, I would end up receiving a random image, e.g. Windows 10 1909 or Server 2019. This is the template in question, as you can see I have clearly selected to deploy the Win10EntTemplate_2004_OSDrive.vhdx:

And what I would end up with after deployment, as you can see a Windows 10 1909 image:

Looking through the Jobs list, I found that the original VHDX file name was set to Windows 10 Template_disk_1.vhdx:

That VHDX file is actually my previous Windows 10 1909 image:

So, it does indeed seem that VMM deployments are selecting .vhdx files at random!

Resolution

Once I identified what was happening, I opened up the VHDX files in question and noticed that when viewing equivalent resources that all three VHDX files are listed:

So it seems that if the Family and Release options all match, then VMM will simply select one at random, even though the Windows 10 2004 .VHDX is explicitly selected within the VM Template, so changing these options to something unique will resolve the issue:

As you can see in the Create Virtual Machine job now, that the correct source file VHDX is being used:

And, finally, I have received the 2004 image:

Until next time.

2 thoughts on “VMM 2019 – VM Template deploying random VHDXs

  • That’s not a bug, that’s VMM operating as designed. You’ve told VMM that the three files are interchangeable – so it will sometimes select alternates even though the specific image is selected.

    • Thanks for your comments, I have updated the post slightly.

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