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

[Pascal Hambourg]

On 26/07/2024 at 04:38, Brian J. Murrell wrote:
> On Thu, 2024-07-25 at 08:54 +0200, Pascal Hambourg wrote:
>
> > You could put /boot in LVM
>
> I used to be a fan of that in fact.  I think I finally gave up fighting
> distro installers that refused to allow you to do that due to the
> distros' fears of /boot in LVM.  I think I recall that also became
> problematic when the LV became fragmented due to extending it without
> space on the disk being available directly subsequent to it.

Indeed extending the /boot filesystem on an additional disk can have 
issues with GRUB. It also affects Btrfs and RAID0.

- If the new disk has a different partition table type (e.g. GPT vs 
MSDOS), then GRUB may not be able to find its partitions because by 
default the core image only includes support for the partition table 
types of the disks containing the /boot filesystem at the time of its 
installation. Reinstalling GRUB generates a new core image which 
includes support for the new disk partition table type.

- The BIOS/UEFI firmware may not expose the new disk to GRUB.

> > So just check if the /boot partition number changed after any
> > other partition change.
>
> That's an interesting tidbit.  I don't think I have ever witnessed this
> renumbering of extended partitions personally.

If you delete sda5, then sda6 and sda7 will become sda5 and sda6. To 
make things worse, the renumbering in the kernel view of partitions 
happens only at the next boot because these partitions are in use, so it 
may be awkward to reinstall GRUB properly.