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Quaracal avatar image
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Quaracal asked YuhanDeng-MSFT commented

Cannot boot a generation 2 VM after restoring from backup

Hello everyone

I can't find a way to boot on a generation 2 VM after it was restored from a backup. It makes me really worried since a good part of our VMs are now gen 2 and their backups are basically unusable.

I mostly use Microsoft Azure Backup Server V3 to backup my VMs, but I have the same issue when exporting them directly with the Hyper-V manager. I tried restoring on multple Windows Server 2016 hosts, I tried the 3 Hyper-V restore options in the wizard, I also tried DPM's "restore directly on a virtualization host". I also tried on my Win10 PC running hyper-V.

When booting the VM, I get the following screen. This happens both on VMs running WS2019 and Ubuntu.

One thing I have not tried is restoring on the same physical host that the backup was taken from-- but considering I would want to restore the backups to a different host in case that host stops working, that wouldn't help me much even if it worked.

Windows Boot Manager : No UEFI-compatible file system was found.
2. SCSI DVD (0,1) : No UEFI-compatible file system was found.
3. SCSI Disk (0,0) : No UEFI-compatible file system was found.
4. Network Adapter (<mac address>) : The network media is disconnect.

No operating system was loaded. Press a key to retry the boot sequence.
Note: Configuration changes may require the virtual machine to be reset.

I tried disabling Secure Boot in the VM before backing up the machine, and enabling the processor compatibility checkbox so it works on hosts with a different CPU. Creating a new VM and attaching the restored VHDX file didn't work either.

Another solution I found in a youtube video was to boot on a Windows ISO, open the command prompt and do some diskpart, bootrec /fixboot and bcdedit, however I haven't managed to mount the system volume in the recovery command prompt (despite the disk showing up in diskpart).

So far I haven't managed to boot on any restored gen 2 VM and I don't think I would be very inclined to go through very a complicated walkthrough to fix the UEFI boot on my VMs in a disaster recovery scenario, especially when restored gen 1 VM are plug-and-play. Has anyone managed to get around this problem?

Thank you.

windows-server-hyper-vwindows-server-backup
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Hi,

I would like to check if the issue has been fixed? If yes, please help accept answer, so that others meet a similar issue can find useful information quickly. If you have any other concerns or questions, please feel free to feedback.

Best Regards,
Danny

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Hi,

I would like to check if the issue has been fixed? If yes, please help accept answer, so that others meet a similar issue can find useful information quickly. If you have any other concerns or questions, please feel free to feedback.

Best Regards,
Danny

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Sorry for being late on giving news.

I have tested the restore process with different gen 2 VMs and I have been able to restore a few of them with no problem. Restore the VM to a folder, import using the hyper-v manager wizard, start the VM and it works. As simple as it should be. However some others just don't boot and I don't understand what they have different. They're all generation 2 running windows server 2019.

My problem is still not solved. I will be seeking help on other forums.

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YuhanDeng-MSFT avatar image
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YuhanDeng-MSFT answered Quaracal commented

Hi,
I’m not sure if this is the cause, but based on my understanding, if you want to use generation 2 VMs, UEFI must be supported.
For your reference:
https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/plan/should-i-create-a-generation-1-or-2-virtual-machine-in-hyper-v

Thanks for your understanding.
Best regards,
Danny


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Hello, I'm not sure to understand what that means. My generation 2 guests run Windows Server 2016, 2019 or Ubuntu 20.04. Right now they are working just fine. The problem I described only occurs when I restore these VMs from a backup.

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YuhanDeng-MSFT answered YuhanDeng-MSFT commented

Hi,
May I ask if there’s any event logs or error messages related to this issue? If any, you can find them by using event viewer.

Thanks for your time.
Best regards,
Danny


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Windows doesn't boot. How is the event viewer gonna help?

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Hi,
It is really important to determine the problem before we can deal with it.
Would you take a look at the link below?
https://docs.microsoft.com/en-us/azure/backup/backup-azure-arm-restore-vms
Please check if there’s any step missing or incorrectly done.
Also, is there any error message or anything when you fail to restore the VM?

Thanks for your understanding.
Best regards,
Danny


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I have not mentioned Azure VMs or the Azure portal in my post. I use MARS to backup on-prem VMs and file servers. This is a Hyper-V issue, not Azure. This link doesn't help.

I reiterate that I cannot read the event log of a VM if that VM doesn't boot in the first place.

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