Just a bit of context:
I am old + handicapped + pretty much isolated, thus certainly not an expert.
But i am happily using debian stable (oldstable by now) since several
years. But since more and more software got outdated, i was interested
to move to bullseye.
In order to have 2 bootable instances (oldstable + stable), i installed
and tested refind, in ordeer to have some safety during the migration
period. I did test the whole setup, which went well. Then installed
bullseye (11.2), but after that, apparently nothing did work any longer.
It took me several days to find out, what destroyed my configuration:
1. bullseye installer had installed grub2 over refind, thereby killing
my setup made for safety purpose.
2. Also, when i tried to boot into the oldstable by hand, it failed to
come up due to some error in fstab, bcoz the installer, while
reformatting the free partition, assigned a new partuuid to it, which no
longer corresponded to the entry in fstab.
3. Furthermore, it installed a grub2 version, that is buggy and which
cannot boot the bootentries, i was used to resort to in case of trouble
(a.k.a. booting straight from an ISO image as an emergency system. The
version installed was known to fail to boot on my kind of hardwae since
several years, and i assumed (my mistake), that a stable debian would
have been fixing the issue by now. (I refer to the links at the bottom).
Ok. After days in panic, i was able to straigthen out my old system and
get it to boot again. But since then, i am totally undecided (and a bit
overwhelmed) with the options, i have to decide about now. What shall i
focus on next?
1. Try the whole process once again and manually downgrade grub2 in
order to have the ISO-boot at hand? (What risk would that involve?)
2. Report a bug (but honestly, i am not skilled enough to even determine
the package(s) causing the mess i encountered. I suspect at least one of
grub2 packages to be involved, but also the installer itself does a
pretty careless job IMHO. (I learned to create proper assertion checks
before shooting a working configuration to death.)
3. Continue to work with oldstable, which increasingly causes problems
due to the outdated software involved. That is, what i am using right now.
Or is there a better option? - Like maybe someone willing to assist in
the process or at least guiding me some steps further?
But i am scared to show the details of what i am doing, as i am a ZFS
user since many years, which is pretty much non-standard!
The bug, i mentioned seems to be related to grub2 2.04 and UEFI booting,
which is necessary on my machine:
https://superuser.com/questions/755641/grub2-boot-error-out-of-memory
https://bugzilla.redhat.com/show_bug.cgi?id=1838633
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1851311
https://ubuntuforums.org/showthread.php?t=2430437
Any hint will be greatly appreciated.
DdB