CentOS6.8, hot-swappable, two pieces of hard disk raid 1, added a new plate (removed from a raid 1 array), mount the new disk times wrong:

mount: unknown filesystem type 'ddf_raid_member'

Checked the, as if need to use for mdadm - assemble/dev/SDC/MNT/SDC, but he still has an error:

for mdadm: device/dev/SDC exists but is not an md array.

Is not only back in the RAID, remove the hard disk RAID set over mount again?