Bug#932085: grub-common: Grub can't load initrd for Xen after upgrade to Buster

[Roger Pau Monné]

On Sun, Jul 14, 2019 at 10:43:43PM +0100, Colin Watson wrote:
> On Sun, Jul 14, 2019 at 01:27:23PM -0700, Slava Kryvel wrote:
> > After upgrade from Debian 9.9 to Debian 10 I have got unbootable system.
> > 
> > I'm using Xen hypervisor, which was also upgraded from 4.8 to 4.11
> > during OS upgrade.
> > UEFI is enabled.
> > 
> > After upgrade was finished, I was unable to boot again to Xen kernel.
> > But normal Debian kernel was still bootable.
> 
> Were there any specific error messages when trying to boot Xen?

Do you have a serial setup for both grub and Xen, and if so can you
paste the full bootlog until you hit the error?

> > I have found a workaround to fix my issue - remove option --nounzip from
> > initrd loading line in grub configuration file /etc/grub.d/20_linux_xen
> > 
> > - module2 --nounzip /boot/initrd.img-4.19.0-5-amd64
> > + module2 /boot/initrd.img-4.19.0-5-amd64
> > 
> > I'm not sure there is issue in config, maybe I did something wrong.
> > So in this case please explain what is correct behavior ?
> 
> I'm using Xen and things seem to work fine for me (without removing
> --nounzip); my Xen system doesn't use UEFI, though.
> 
> I'm CCing a few folks who've contributed to GRUB's Xen support in one
> way or another in the recent past; hopefully at least one of them can
> help here?

That's certainly weird, I'm using grub2 with UEFI (the packages with
the multiboot2 backports provided by cjwatson for stretch) and
--nounzip seems to work just fine there.

Maybe you can give a try to the packages from stretch in order to make
sure it's grub2 the culprit of the issues you are seeing?

Roger.