Bug#621786: One Thought/Thing to Try

[Scott Schaefer]

I have spent some time attempting to duplicate this problem w/o much 
success.

I have duplicated your setup as closely as I can, which, unfortunately 
is not real close:

1) I am running under QEMU, and
2) I have smaller drive; unfortunately, I don't have a spare TB drive 
lying around :-((

I read the thread on the QNAP site you linked to as well.

I have one thing that should be simple to try:

Change your /etc/mdadm/mdadm.conf DEVICE line to read:

DEVICE /dev/sd*

Then, retry mdadm --assemble ...

If it still fails, running under strace again may help.

If it "succeeds", then I think there is reasonable chance this is 
related to the mtdblock device(s).  Update the initramfs, reboot, and 
see if the devices are normal on startup.