Thomas Schmitt (12024-01-24):
> i cannot make qualified proposals for the GRUB question, but stumble over
> your technical statements.
It was by far the most interesting reply. Better somebody who really
understood the question, realized their limitations and knowingly
replies with an interesting tangential than the opposite.
> Although it would be unusually small, it is possible to have a GPT of
> only 4 KiB of size:
> - 512 bytes for Protective MBR (the magic number of GPT)
> - 512 bytes for the GPT header block
> - 3 KiB for an array of 24 partition entries.
>
> Question is of course, whether any partition editor is willing to create
> such a small GPT. The internet says that sfdisk has "table-length" among
> its input "Header lines". So it would be a matter of learning and
> experimenting.
Interesting. Indeed, “table-length: 4” causes sfdisk to only write 3
sectors at the beginning and 2 at the end. I checked it really does not
write elsewhere.
That makes it possible to use full-disk RAID on a UEFI boot drive. Very
good news.
> > we have to partition them and put the EFI system partition outside
> > them.
> Do you mean you partition them DOS-style ?
No, GPT. More and more firmwares will only boot with GPT. I think I met
only once a firmware that booted UEFI, 32 bits, with a MBR.
GPT
├─EFI
└─RAID
└─LVM (of course)
Now, thanks to you, I know I can do:
GPT
┊ RAID
└───┤
├─EFI
└─LVM
It is rather ugly to have the same device be both a RAID with its
superblock in the hole between GPT and first partition and the GPT in
the hole before the RAID superblock, but it serves its purpose: the EFI
partition is kept in sync over all devices.
It still requires setting the non-volatile variables, though.
Thanks.
Regards,
--
Nicolas George
