On 11/21/2013 12:15 AM, David F. wrote:

mdadm: /dev/sdf is identified as a member of /dev/md/ddf0, slot 4.
mdadm: /dev/sde is identified as a member of /dev/md/ddf0, slot 3.
mdadm: /dev/sdd is identified as a member of /dev/md/ddf0, slot 2.
mdadm: /dev/sdc is identified as a member of /dev/md/ddf0, slot 1.
mdadm: /dev/sdb is identified as a member of /dev/md/ddf0, slot 0.
mdadm: ignoring /dev/sdb as it reports /dev/sdf as failed
mdadm: ignoring /dev/sdc as it reports /dev/sdf as failed
mdadm: ignoring /dev/sdd as it reports /dev/sdf as failed
mdadm: ignoring /dev/sde as it reports /dev/sdf as failed
mdadm: no uptodate device for slot 0 of /dev/md/ddf0
mdadm: no uptodate device for slot 2 of /dev/md/ddf0
mdadm: no uptodate device for slot 4 of /dev/md/ddf0
mdadm: no uptodate device for slot 6 of /dev/md/ddf0
mdadm: added /dev/sdf to /dev/md/ddf0 as 4
mdadm: Container /dev/md/ddf0 has been assembled with 1 drive (out of 5)

That looks really weird. The (healthy?) devices sdb-sde are ignored
because they report sdf as failed, and then sdf is used for assembly?

I have no idea at the moment, I need to read the code.

Output of dmraid --raid_devices command:
/dev/sdf: ddf1, ".ddf1_disks", GROUP, unknown, 285155328 sectors, data@ 0
/dev/sde: ddf1, ".ddf1_disks", GROUP, ok, 285155328 sectors, data@ 0
/dev/sdd: ddf1, ".ddf1_disks", GROUP, ok, 285155328 sectors, data@ 0
/dev/sdc: ddf1, ".ddf1_disks", GROUP, ok, 285155328 sectors, data@ 0
/dev/sdb: ddf1, ".ddf1_disks", GROUP, ok, 285155328 sectors, data@ 0

This seems to support then notion that something's wrong with /dev/sdf.

Martin