Re: UUIDS

[Felix Miata <mrmazda@earthlink.net>]

mick.crane composed on 2023-05-28 00:37 (UTC+0100):

> I'm sure it used to be that you could swap linux discs between PCs and 
> it would sort itself out but I try swapping disks about and booting and 
> they complain
> "Cannot find UUID..lots of identifying numbers"
> and gives intramfs prompt.
> Am I supposed to be able to sort it out from there?
> like how?

It depends on what can't find what. If UEFI BIOS are involved, it can be both
easier and harder to deal with than for MBR booting. Lots of buggy UEFI BIOS are
around to complicate what should make things easier harder. A fix could be as easy
as either clearing NVRAM of existing entries, or booting removable media to run
efibootmgr to either clear existing entry(s) and/or add a new one. It's also
possible the ESP partition's UUID is included in the initrd and needs to be
overridden with rd.hostonly=0 and/or rd.auto=1 on Grub's linu line.

So tell us, is this with UEFI, MBR, or a mixture? What hardware was in the source,
and what in the destination? How many disks in the destination? How many operating
systems on the disk(s)? Can you boot an installed system using installation media?

As always, as long as required drivers are included in the initrd, if you know
enough about device names, filesystem LABELs and filesystems involved, booting can
be accomplished manually from a Grub prompt without involving UUIDs, but from an
initramfs prompt it can be harder or impossible.
-- 
Evolution as taught in public schools is, like religion,
	based on faith, not based on science.

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata