On Wed, Sep 17, 2025 at 6:10 PM Richmond <[email protected]> wrote: > > Felix Miata <[email protected]> writes: > > > Richmond composed on 2025-09-17 18:14 (UTC+0100): > > > >> Why did this all go so wrong? Why would > >> Debian 13 boot without displaying Grub, even though it had a timeout of > >> 5 seconds? > > > > Grub's upstream default changed to disabling os-prober, so 13's Grub > > doesn't look > > for anything else, and since the new installation had only one kernel to > > offer, > > there was no reason to assume other than the sole known kernel to boot. > > Change > > /etc/default/grub to enable os-prober, and following next update of > > grub.cfg, you > > should find 12, 13 and openSUSE in your 13 Grub menu. > > I didn't find a grub menu, and os-probe was running. It was all > puzzling. > > I have two EFI System partitions so this must have been the cause of the > problem. In the old days installation used to say "you already have > grub, do you want to overwrite it?" or something like that but there was > no such question. Immediately after the installation I did see a Debian > 13 grub menu, but trying to fix Debian 12 caused it to vanish and never > come back. > > So how is it that re-installing grub from the boot media rescued Debian > 12, but re-installing grub from Debian 12 did not?
Isn't the os-prober disabled nowadays? I think that would explain why other Linux installations are not being found. Otherwise, I think you will need to provide a lot more information. And personally, I would not putz around with GRUB. UEFI is perfectly capable of managing and booting multiple OSes. ... Unless there is a specific need, like chain loading. > At some point I did these commands which may have been a bad idea: > > sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi > --bootloader-id=debian12 > sudo update-grub > > >From Debian 12 I see: > /boot/efi/EFI# ls -l > total 20 > drwx------ 2 root root 4096 Oct 31 2014 Boot > drwx------ 2 root root 4096 Dec 28 2023 debian > drwx------ 2 root root 4096 Sep 17 17:13 debian12 > drwx------ 3 root root 4096 Jul 6 2014 Dell > drwx------ 4 root root 4096 Oct 31 2014 Microsoft > > The Opensuse one is: > ls -l /mnt/EFI > total 4 > drwxr-xr-x 2 root root 2048 Apr 7 2024 boot > drwxr-xr-x 2 root root 2048 Apr 7 2024 opensuse Jeff
