Re: Drops to command prompt; configfile /grub2/grub.cfg needed to boot

[Pascal Hambourg]

On 25/07/2024 at 01:54, Brian J. Murrell wrote:
> Fair enough.  But I don't think Fedora has update-grub.  I think that's
> a Debian/Ubuntu-ism.  /boot/grub2/grub.cfg refers to grub2-mkconfig.

Then run "grub2-mkconfig > /boot/grub/grub.cfg".

> When I do that and compare the newly generated grub.cfg with the one I
> edited they are the same.  :-P

Even the UUIDs ?

> > It should be --boot-directory (or nothing, as /boot is the default).
>
> Just tried that and it now boots to the menu.  So either the above (or
> the new kernel update that has happened in the meanwhile) fixed it.

A kernel update would only rebuild grub.cfg, not run grub2-install.

> > I advise against using a logical partition for /boot. When installed
> > on the same disk, GRUB uses the partition number to identify the boot
> > partition but logical partition nombers are not stable, they may
> > change on creation or removal of another logical partition.
>
> Unfortunately I don't have a choice.  The /boot that I replaced (sda5)
> was logical (extended) also because the computer vendor used up 3
> primary partitions themselves:

Too bad. You could put /boot in LVM so that GRUB uses a UUID to locate 
it, but GRUB has an obscure wrap-around bug after ~200 LVM metadata 
changes (fixed in next 2.13 unless your distribution backported the 
fix). Converting MSDOS to GPT is not an option either because of 
Windows. So just check if the /boot partition number changed after any 
other partition change.