General :: Mdadm - RAID5 To RAID6, Spare Won't Become Active

I've been playing with this for hours, and have been unable to figure it out. I tried to convert my RAID5 array of 4 active disks and 1 spare to a RAID6 with 5 active disks.

I did this:

Code:
mdadm --grow /dev/md4 --raid-devices 5 --level 6
Here is what I have on /dev/md4:

Code:
/dev/sde1 active
/dev/sdg1 active
/dev/sdj1 active
/dev/sdf1 active
removed
/dev/sdh5 spare
code....

but it tells me that /dev/sde is busy, and then that it has a bad superblock (From what I've read, I'm sure the bad superblock is just because of the "busy" message). I've tried this with the -f option, too, with no luck.