Re: mirroring existing boot drive sanity check

[Wols Lists <antlists@youngman.org.uk>]

On 11/08/2022 22:26, Pascal Hambourg wrote:
> However I do not think it is possible to cleanly boot from an 
> unpartitioned drive used as a software RAID member, as a RAID capable 
> boot loader could hardly fit in the 4-KiB area before the RAID 
> superblock. So you still have to create a partition table on the raw 
> drives. Also, if you use GPT format and GRUB boot loader, you need to 
> create a small (100 kB to 1 MB) partition with type "BIOS boot" (or 
> libparted bios_grub flag).

Firstly, is there a 4K block there? iirc it's only 1.2 that leaves said 
block.

And secondly, does raid assume that 4K space belongs to it? I know it's 
seen as a safety space, so there's nothing permanent left there, but 
that's no guarantee raid doesn't think "that's mine, I'll stash 
something there temporarily". After all, the space allocated explicitly 
begins at the start of the 4K.

(That's completely different to the rouge tools the space is there to 
protect - those tools that think "that's nobody's, I'll just grab it".)

Cheers,
Wol