Bug#569359: mdadm -Ds insists on /dev/md/X device presence

[Martin Michlmayr]

So I briefly booted into the last stable release of Debian to see why
it works.  The difference here is that mdadm shows /dev/mdX device
names by default (there was no map file in /var/run):

  /var/run # mdadm --examine --scan --config=partitions
  ARRAY /dev/md0 level=raid1 num-devices=2 UUID=01d4e1dd:5a6df36c:306f37c8:5b3189c6

and since /dev/md0 exists everything is fine.

It seems to me that at some point (probably with mdadm 3.1.1), the
output of --examine --scan changed to /dev/md/X device names and this
is when things (with Debian installer) started to break since we only
have /dev/mdX.

Presumably, the change to /dev/md/X was intentional (Neil), so maybe
we should:
  - ensure that mdadm in Debian installer ships an udev rules that
    creates /dev/md/X
  - change the creation of RAID devices from
      mdadm --create /dev/md$FOO
    to
      mdadm --create /dev/md/$FOO

Comments?
-- 
Martin Michlmayr
http://www.cyrius.com/