> mbr disks would grab four partitions (modulo disklabel ones that were
> found). And so on.

The mbr extended partitions require more care.
Correctly formatted, they are a linked list in increasing sector numbers.
So if you allocate some free space (or free an extended partition)
then the numbers of any partitions further down the extended one
change.  This isn't really acceptable...

The information required to tie this down need only be in a file
in the root filesystem though - it doesn't need to be on the same
disk as the extended partition.

If you can save enough stuff to generate a 'reasonably likely'
disk fingerprint, you should be able to detect a disk being moved
to a different controller - and reassign it the same logical disk
number.

	David

-- 
David Laight: david@l8s.co.uk