Re: A question about VM configuration

[Paul Leiber <paul@xxxxxxxxxxxxxxxx>]

On 23.05.25 8:15 AM, Mario V. Guenzi wrote:
> Hello Attila,
>
> T.Y.
>
> The problem isn't transferring or cloning the VMs — I can do that 
> without any issues using |dd| or Clonezilla. The real problem, as Paul 
> mentioned yesterday, is that there's a bug in OVMF which has existed 
> since 2013 and still hasn't been fixed.
Mario, I'm not sure we are talking about the same bug. The bug in the 
Debian ovmf package is caused by architectural changes in ovmf not 
reflected in the Debian package, namely the creation a xen-specific ovmf 
version [1] which doesn't exist in Debian ovmf package 2022.11-6. (The 
change in the code happened in 2019, so I am not sure which bug you are 
referring to which is supposed to exist since 2013.) Lacking this ovmf 
version, uefi boot of xen DomUs fails. Other distributions are including 
this xen-specific ovmf version, Debian doesn't (yet?). Installing the 
previous Debian ovmf package is sufficient to circumvent this problem. 
building the right ovmf version and using it fixes this problem (more 
details can be found in the bug report and replies). As Devuan is based 
on Debian, I thought it might be probable that this bug has been taken 
over by Devuan.
To make that clear: I am in no position to know precisely what the cause 
of your issue is, I am just making assumptions. The actual root cause 
might be something else.
> So, when I start the VM with the |firmware = 'ovmf'| or |uefi| option 
> (which are essentially the same), it crashes and reboots after a few 
> seconds.
> Now I need to find a way to create a Windows 10 ELTS machine that can 
> boot without UEFI firmware, and then, once it's up and running, try 
> cloning only the partition I need from the old VM.
> The issue is that even using the configuration parameters Joos gave me 
> yesterday, the machine doesn’t work — it doesn’t even boot from the 
> CD-ROM.
You could consider trying one of the workaround/fixes mentioned above  
(using an older ovmf version or building ovmf yourself). This might be 
less effort than the path you describe, but of course YMMV. (Switching 
to a previous ovmf version is one shell command, at least in Debian. If 
this change is effective, this would also rule out other causes at the 
same time.)
Paul

[1] 
https://lore.kernel.org/all/20190813113119.14804-1-anthony.perard@xxxxxxxxxx/#t