[NCLUG] RAID array not started on re-boot

[Kevin Olson]

As you surmised, we are using the partitions /dev/sda1 and /dev/sdb1 to
form the array, and not the whole disks. There was an issue at some point
in time in using the full disks, and since then we've always used the
partitions. If one can reliably use the whole disks, I would think life
would be easier.

It is just so strange that the "mdadm --assemble /dev/md1" worked without
an issue, yet at boot it follows the logic you noted with the information
from the "mdadm --misc --examine /dev/sda /dev/sdb" command.

>From your explanation, I can see where the scan finds the /dev/sda and
/dev/sdb (the whole disks) and perhaps creates the (separate) arrays from
those on boot, due to perhaps old data. We replaced one of the disks a few
months ago, so I presume that explains the difference in the number of
events.

It is a bit difficult to tear the array apart at the moment, otherwise I'd
follow your advice and zero the disks. I believe I read somewhere that in
the /etc/mdadm.conf, it is possible to specify which devices should be
looked at. Should I consider modifying that configuration to explicitly
list the partitions? Would this approach make any difference on boot?

Thank you for the help!