I notice that my raid array is not starting up properly after I boot a new kernel, 4.3. I figured out that I could manually assemble the array with the command below. However, I want to automate the process.
mdadm --assemble --verbose /dev/md127 /dev/sdb1 /dev/sdc1
The solution is making the necessary changes in mdadm.conf file so that the system can see the array following a reboot. Here is my mdadm.conf file.
#mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#
# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
#DEVICE partitions
DEVICE /dev/sd[bcdjkl]1
# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes
# automatically tag new arrays as belonging to the local system
HOMEHOST
# instruct the monitoring daemon where to send mail alerts
MAILADDR root
# definitions of existing MD arrays
ARRAY /dev/md127 metadata=0.90 UUID=a42d6399:f6d2b49c:924717a0:72ea5865 devices=/dev/sdb1,/dev/sdc1
# This file was auto-generated on Mon, 16 Jul 2012 06:37:54 -0400
# by mkconf 3.1.4-1+8efb9d1+squeeze1