Comment 67 for bug 136252

And there you go.

+1 for fix on my up-to-date 64-bit Maverick Server :)

I'm loving it. Been rebuilding my 6*2TB RAID6 for three days now, figuring something went wrong a couple of times.

Then I found out the detection issue and then this bug is easily found.

FWIW, I've got an array created using:
mdadm --create /dev/md20 --level=6 --raid-devices=6 -c 256 -e 1.2 --name=SATAs /dev/sd[cdefgh]

The infamous md_d127 device kept showing up as well.

doing an
mdadm --stop /dev/md_d127
mdadm --assemble -v /dev/md/SATAs /dev/sd[cdefgh]
then properly reinitalized the array.

The only thing that would work was manually adding
ARRAY /dev/md20 level=raid6 num-devices=6 metadata=01.02 name=ubuntu:SATAs UUID=10b2a833:0fac6b94:3224150e:0aeefa84 devices=/dev/sdc,/dev/sdd,/dev/sde,/dev/sdf,/dev/sdg,/dev/sdh

to /dev/mdadm/mdadm.conf. Named array (/dev/md/SATAs) will not work.

Your mdadm/initramfs correctly detects & activates the array without anything in /etc/mdadm/mdadm.conf, albeit as /dev/md127, NOT as /dev/md/SATAs

As a fortunate side-note, yours also correctly reports the metadata superblock version as 1.2, as opposed to 01.02 in the other, leading to errors.