Ubuntu Servers :: RAID6 Fails To Re-assemble After Restart (left With Spare Device In /dev/md_dX)

As per [URL] I built a RAID6 array. yay. In the end it completed.

Code:

fermulator@fermmy-server:~$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md2000 : active raid6 sdo1[3] sdn1[2] sdm1[1] sdl1[0]
3907026944 blocks level 6, 64k chunk, algorithm 2 [4/4] [UUUU]

To test stability, I rebooted the system, but on reboot, the array wasn't assembled correctly. Basically it had one device in "md_d2000", as a spare. So I stopped that device with

Code:

sudo mdadm --stop /dev/md_d2000

The superblocks looked good ...

Code:

fermulator@fermmy-server:~$ sudo mdadm -E /dev/sd[lmno]
/dev/sdl:
Magic : a92b4efc
Version : 00.90.00

[code]...

I don't have any important data on the array yet ... so I zero'd the superblocks on all devices, deleted the partitions, and started over .. here I go again:

Code:

md2000 : active raid6 sdo1[3] sdn1[2] sdm1[1] sdl1[0]
3907026944 blocks level 6, 64k chunk, algorithm 2 [4/4] [UUUU]
[>....................] resync = 0.7% (14164844/1953513472) finish=313.7min speed=102999K/sec