vSphere to Hyper-v BIOS partition.

[rschmeits]

We have several Linux VMs that use BIOS-based boot partitions.
When we restore them through the GUI into our 2025 Hyper‑V environment, the system defaults to creating a Gen2 VM.
After restore, the VM fails to boot because it requires Gen1.
Our current workaround is to delete the auto‑created VM, re‑import it manually, choose Gen1, attach the disks, and then it boots correctly.
This process works but is clunky and requires too many manual steps.
We’re looking for a way to streamline or automate this setup.
Any suggestions?

Note we are migrating from vSphere 7.0 to MS Windows 2025 Hyper-v
Thanks.
Roger.

[haslund]

There are cases where the VM will be restored as a Gen1 VM.

It would be a good idea to check the Guest OS disk layout:
- Check if the boot partition is marked EFI or BIOS inside the VM
- Check if you have GPT partitions or MBR ones

Can you share the output?