On Wed, Oct 7, 2020 at 7:10 PM Noah Meyerhans <[email protected]> wrote: > > On Tue, Oct 06, 2020 at 02:58:22PM +0200, Matteo Croce wrote: > > The official Debian Buster image breaks when upgrading to bullseye. > > GRUB fails like: > > > > error: symbol 'grub_file_filters' not found. > > Entering rescue mode... > > grub rescue> > > > > I see the error in the HyperV graphic console, > > I could probably recover it if only GRUB uses the serial for IO. > > This is likely the same underlying issue as the one described in > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=966575 The issue is > likely that the MBR code on your instance was not updated with the grub > package upgrade due to block device differences between the environment > in which grub originally configured the drive MBRs and the environment > in which the upgrade ran. >
Don't really know, it was a GRUB UEFI installation, FYI > The workaround would be to to use grub-install to write the updated MBR > code to the correct block device. Naturally you need to do that before > you reboot. > > If you've already rebooted and need to recover, you'd need to boot some > kind of recovery environment (possibly involving launching another VM > and attaching the relevant block device to it). > > I don't know that there's anything we can do in the cloud images > specifically to help with this situation. > That's what I did, started another VM and attached the disk, then ran grub-install in a chroot. No luck. -- per aspera ad upstream
