SS: The subject.
LS: the entire post.

Running a recent apt-get update/upgrade/dist-upgrade brought two of our
five Devuan-beowulf systems down.

the cultprit appears to be the apt-get dist-upgrade which installed
this kernel upgrade;
Linux system 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19)
x86_64 GNU/Linux.

It appears to be(is reproducible) hardware related.

The three that worked were all simple motherboard with single hardisk
where the hard disk/storage appears as /dev/sda. The grub update(?) on
these systems were all successful and they seamlessly rebooted.

The two that failed both had mu;tiple hard-disk and the grub
bootloader was not installed the frst hard-disk '/dev/sda' and both
system dumped to a grub interface on reboot.

I've recently been attempting to rebuild my domain mailer and the error
was reproduced when the install from a Devuan-beowulf 3.0 install DVD
also borked(failed on reboot) to grub interface when I asked it to stall
the boot loader to /dev/sdb. Luckily, I could just move the chose root
disk to /dev/sda and repeat the complete install.

I was able to use that same on my desktop machine first, before
starting to build up the new mailer. It was a simple(?) matter of
swapping SATA cables to put the storage holding the grub loader so it
appeared on /dev/sda. This was easy as the deskto boxen is largely sans
covers as I'm waiting for a kernel that will recognised an AMD 5700XT
GPU.

The real problem is the other machine which functions as the main
raid based backup machine and has a large number of internal heavy hard
disks that is hernia inducing to lift. I'm really hoping to be able to
solve this one by keyboard rather than hardware hacking.

Grub lists the partitions as (HD0), (HD1,gpt1).....(HD1,gpt5) and
(HD2...5).

Grub lists the "root=(HD1,gpt1)", but no matter what I enter,
'autocomplete' isn't working and nothing works.

Anyway, if anyone has any practical ideas, thanks.

In that 'when it rains, it pours' department, the backup machine has
the only 'accessible' copy of the configuratin settings for the mail
server, which managed to let 'out the magic smoke(literally crash and
burn when a black out bounced them power a few times.

The really AAARGH part is the mail server hard disk is just fine, but
it is as Single Ended SCSI 1 hard disk and absolutely none of the
matching interface cards will work in any of my modern systems.

I am really not looking forward to configuring the new mail server from
first steps. My webfu isn't turning up even a decent practical manual
atm. Perhaps another nights sleep.