On Sat 31 Jan 2026 at 16:58:39 (-0700), D. R. Evans wrote:
> I haven't yet copied the data off the old disk, because there's a lot
> of work to be done configuring things on the new system first (I don't
> want to simply copy system configuration files from the old disk: that
> seems a dangerous thing to do; fine for user data, but not for system
> configuration). But once I'm happy that I have a properly functioning
> system on the new disks, I'll rsync the user files across to the new
> disks and put this all behind me.
>
> Several times over the past couple of weeks I have found myself
> longing for a good old-fashioned O'Reilly book on GRUB (for which the
> cover would be obvious :-) ), but it seems that there was never such a
> thing -- and in any case it would be long out of date now. And that
> kind of detailed book dedicated to a relatively small aspect of Linux
> it seems is no longer produced or updated.
>
> I do wish that I at least understood what made my situation turned out
> to be so unresolvable. But at some point one just throws in the towel:
> when I looked around the room and saw a multitude of sheets of e-mail
> printouts scattered around and covered with scribbled annotations, to
> the point that I could no longer keep track, I realised that, as they
> say, discretion is the better part of valour, and I should start
> afresh with a new system.
>
> Thanks to everyone who tried to help. It's quite frustrating that I
> can't change the subject to include "SOLVED", but I suppose that's
> life.
If you're starting over, have you thought about partitioning the
drives as GPT rather than MBR? Apart from being able to future-proof
the disks with respect to new host machines, there is one advantage
with the BIOS booting that you're currently using: you can provide
a safe place for Grub to store its core image.
When I partition my disks, I place a 3MiB BIOS Boot Partition at the
start, setting its type to EF02, which reserves it for Grub to use.
The next partition is the (future) UEFI ESP, which BIOS booting
doesn't require, so I set its type to Linux Swap, 8200. I make this
partition 496MiB, which aligns the next partition to start at
sector 1024000. The rest of the disk holds the "useful" partitions,
for OSes, data, swap, etc.
A disk like this can be booted by Grub in a BIOS or an EFI machine.
With BIOS:
Number Start (sector) End (sector) Size Code Name
1 2048 8191 3.0 MiB EF02 BIOS boot partition
2 8192 1023999 496.0 MiB 8200 Linux swap
3 1024000 … … … … …… … …
With EFI:
Number Start (sector) End (sector) Size Code Name
1 2048 8191 3.0 MiB EF02 BIOS boot partition
2 8192 1023999 496.0 MiB EF00 EFI System
3 1024000 … … … … …… … …
The sector numbers are for a 512-byte logical sector size. I partition
disks with gdisk, which makes it easy to set good alignments.
Cheers,
David.
