[Libguestfs] ovirt VM image to BM

[Richard W.M. Jones]

On Wed, May 18, 2022 at 01:20:27PM +0200, Guilherme De Oliveira Santos wrote:
> Greetings masters,
>
> I got pointed to you guys as experts on smtg I'm struggling with.
> I'm trying to move an ovirt vm raw image to a bm machine and though
[bm = baremetal]
> I could do it successfully using dd (got able to see and work with
> the partitions and the data fine), I couldn't boot the disk.
>
> It may be an issue with drivers (like the virtio drivers), but idk,
> and I'm wondering if someone has done smtg similar or could help
> somehow with the process.

So in IRC we established that it's a RHEL 8.6 guest, and that it
doesn't get as far as grub.  The virtual machine boots with UEFI and
the physical machine boots with BIOS which is why grub doesn't work.

Conversion of a machine from UEFI to BIOS is usually quite tricky.
Are you sure the baremetal machine doesn't support UEFI booting?
Almost anything made in the last 10 years should, although you may
have to adjust the firmware ("BIOS") configuration.

After that it'll probably not have the right drivers in the initramfs.
Symptoms would be that it gets to grub, then boots the kernel, but
fails when mounting the root filesystem.  Luckily this is easier
to solve - identify which drivers are needed for the target
hardware and before copying across, run “dracut --add-drivers ..”
You'll have to read the dracut man page closely.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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