Possible workaround (or way to undo the name assignment from the raid w/o losing data.)
If I reset the name (from raid_disk_2), it auto assembles now on reboot properly.
Steps I used to undo the --name setting when I built the raid, w/o data loss or resync.
* unmount any mounted fs on raid, and stop the raid
* changed /dev/md/raid_disk_2 entry in mdadm.conf to /dev/md5, and removed name=
* reset the super-minor: mdadm -A -U super-minor /dev/md5
* stop the raid again: mdadm --stop /dev/md5
* reset the name: mdadm -A -U name /dev/md5
* reset the mdadm.conf: /usr/share/mdadm/mkconf force-generate /etc/mdadm/mdadm.conf
* reset the various initramfs images: update-initramfs -k all -u
Now /dev/md5 is fully assembled upon boot.
Conclusion: I will not mess with the name field when creating raids for now. It may be due to my misunderstanding of the purpose of the name field (apparently it works only if it is a number - the same as the super-minor), or there is a bug somewhere.
Possible workaround (or way to undo the name assignment from the raid w/o losing data.)
If I reset the name (from raid_disk_2), it auto assembles now on reboot properly.
Steps I used to undo the --name setting when I built the raid, w/o data loss or resync.
* unmount any mounted fs on raid, and stop the raid mdadm/mkconf force-generate /etc/mdadm/ mdadm.conf
* changed /dev/md/raid_disk_2 entry in mdadm.conf to /dev/md5, and removed name=
* reset the super-minor: mdadm -A -U super-minor /dev/md5
* stop the raid again: mdadm --stop /dev/md5
* reset the name: mdadm -A -U name /dev/md5
* reset the mdadm.conf: /usr/share/
* reset the various initramfs images: update-initramfs -k all -u
Now /dev/md5 is fully assembled upon boot.
Conclusion: I will not mess with the name field when creating raids for now. It may be due to my misunderstanding of the purpose of the name field (apparently it works only if it is a number - the same as the super-minor), or there is a bug somewhere.