I did some research, and I think I am getting a bit closer. The
information is a bit cryptic, but if I understand correctly, first I
need to set up a DDF Container. I think the command should be:
mdadm --create /dev/md70 /dev/loop[0-2] missing --raid-devices 4
--metadata=ddf-????
I'm not sure what the metadata parameter should be, however, or how
to find out. The MAN page only lists ddf as a proper metadata style. The
superblock is definitely at the end of the RAID members. To me this
suggests a V0.9 or 1.0 superblock. Mdadm reports version 01.00.00, but
that is a different format from the my v1.2 arrays.
Then as I understand it, I need to create a member array:
mdadm --create /dev/md7 /dev/md70 --raid-devices 4 --level 5 --chunk=512(?)
I think the chunk size should be 512, right? Mdadm reports the
chunk size to be 1024 sectors, but the sectors are 512 bytes, so 1024
sectors would be 512KB. Should the chunk size be specified for the
container, as well, or perhaps only the container?
