On 03/11/17 00:47, Wols Lists wrote:

On 31/10/17 18:11, Wols Lists wrote:

quoted

It's possible - I wouldn't know - that the existence of the MBR stops
mdadm looking for a superblock that applies to the whole drive, which
could explain why those drives have disappeared.

Just been digging in the code - function check_raid - I think if you
pass a drive to mdadm it checks the drive for a superblock, and doesn't
look for whether a partition table exists. So I think that's that
explanation blown out the water ... :-(

:-) Thanks for looking.

As I mentioned, I think I created the array via Xubuntu.

As far as I remember I didn't partition any of the drives - just added
them to the array and I think it effectively created one partition
across the whole array (which would make sense why you can't see
partitions on individual drives)

I am pretty sure that is trashed, but I like to try and understand these
things !

B. Rgds
John