Re: md RAID5: Disk wrongly marked "spare", need to force re-add it

[Ben Bucksch <linux.news@bucksch.org>]

Oliver Schinagl wrote, On 14.04.2013 19:30:
> mdadm --assemble --run --force /dev/md0 /dev/sd[1-7].
> Make sure to mdadm --stop /dev/md0 before trying to assemble it. 
# mdadm --stop /dev/md0
mdadm: stopped /dev/md0
# mdadm --assemble --run --force /dev/md0 /dev/sd[jlmnopq]
mdadm: failed to RUN_ARRAY /dev/md0: Input/output error
mdadm: Not enough devices to start the array.
# cat /proc/mdstat
md0 : inactive sdj[0] sdq[7] sdn[6] sdp[5] sdo[4] sdm[3]
       5860574976 blocks
(Note that sdl is not even listed)
# mdadm --re-add /dev/md0 /dev/sdl
mdadm: re-added /dev/sdl
# cat /proc/mdstat
md0 : inactive sdl[8](S) sdj[0] sdq[7] sdn[6] sdp[5] sdo[4] sdm[3]
       6837337472 blocks

Now, sdl is listed, but as spare. I need it to be treated not as spare, 
but as good drive with correct data (well, almost, 2 events off only). 
How do I do that?