On October 19, 2017 3:58:48 AM PDT, Wols Lists [off-list ref] wrote:

Okay. First thing I'd try is temporarily get rid of mdadm.conf. You
don't actually need it. Then do "mdadm --stop /dev/md0" followed by
"mdadm --assemble --scan".

Ok, so doing the stop, then assemble scan gets me :

/Dev/MD/0 assembled from 5 drives - not enough to start the array.
No arrays found in config file or automatically.

This was after moving the mdadm.conf temporarily.

If that doesn't work, then try assembling the array explicitly, ie
listing all the drives. I can't remember whether order is important -
so
long as you don't specify --force it'll either work or fail, it won't
do
any damage.

Looks like it's failed.  I ran:

mdadm --assemble /dev/md0 /dev/[abcde]1 /dev/sd[fgh] 

Due to having to use a cell phone to respond I didn't type everything out here, but that's the idea. Running that, I got:

No superblock find on sdf expected magic a92b4efc, got 00000000
No raid superblock on sdf
Sdf has no superblock assembly aborted

This is where I've been stuck. I read a post a couple nights ago about zeroing the superblock on the drives that report no superblock, but it seems they are already zeroed? My lack of experience here isn't helping.