Hyper-V - Moving VM to a new host

[HCHTech]

I'm replacing an existing Hyper-V server, and I had to move an existing workstation VM from the old server to the new one. This VM is running an old piece of software and the os is Windows 10. So what I did:

• Shut down the VM on the old server
• Copy the machine & disk files for that VM to the new Hyper-V host
• Imported the VM using Hyper-V manager.

This worked just fine, but while the machine would start up, I couldn't log in with a domain account. I got the not-altogether-unexpected error of

"The trust relationship between this workstation and the primary domain failed."

I fixed this by logging in with a local admin account, then unjoining and rejoining the domain. All is well now, but I'm wondering if I should have done things differently. This was a low-impact issue in this case, but I'm wondering how the process would change if I was moving a server VM, or a Domain Controller VM...

 

[YeOldeStonecat]

I've moved many virtual machines from one HV host to another...I only move the VHD files. I recreate the machine in the new HV hosts HV Mangler...(which is what the machine files hold)..but it's really easy enough to remember..."OK, it had 4x cores, and 32 gigs of RAM". So I always preferred just moving the virtual disks..and building the machine in HV Manager...and then pointing its disks to where I put the disks.

Not the cause of your problem though.
I suspect...this virtual guest..."broke" its relationship with active directory while on the old hyper-V host. Perhaps its DNS settings in TCP/IP v4...were not pointing to just the DC or were pointing externally, or severed...due to some Hyper-V switch and firewall thing. And it has been logging in with cached credentials for a long time.

The move to a new host, a new virtual network adapter...perhaps properly now taking DNS correctly and communicating with active directory on the DC and the problem now surfaces.

That's my hunch and I'll bet a pint of Guinness on it!

 

[HCHTech]

I have no trouble believing your supposition. This server migration took....checks notes.....54 billable hours. Bad handoff from old techs, no one at the client knew about the 8 or 9 LOB apps they depended on (save the one person that did, but left the company a year ago), the vendor support was......barely adequate. Kind of a mess, but it's all working now, and I'm confident that things are configured in a more best-practices way. On to the next one!

 

[Sky-Knight]

Moving the drive means rebuilding the VM itself, which will futz with activation, network settings, and a few other things. Yes, it works! And that's usually how we do it.

But if you want something a little more automated, This thing is magic: https://www.starwindsoftware.com/starwind-v2v-converter

Fire it up, aim it at the VM, or run it within the VM, and aim it at the target host... click GO... come back later to a moved working VM.

 

[HCHTech]

This thing is magic:

Ooh, interesting - any idea of the pricing? I'm not keen to get on their mailing list just to find out what it costs. Their website just says "request a quote"....yeah, no -haha.

 

[Sky-Knight]

Ooh, interesting - any idea of the pricing? I'm not keen to get on their mailing list just to find out what it costs. Their website just says "request a quote"....yeah, no -haha.

You managed to miss the big green "free software" label above the name and the download button?

Starwind sells software that makes virtual SANs, this is their loss leader to get interest and name recognition. Just use the thing!

 

[britechguy]

Ooh, interesting - any idea of the pricing?

Free for the piece of software that links to. They've got lots of non-free stuff, too, but the one referenced is under their Free Software category on their downloads page.