DEVICE /dev/sda1 /dev/sdb1
DEVICE /dev/sda2 /dev/sdb2
DEVICE /dev/sda3 /dev/sdb3
#
ARRAY /dev/md1 devices=/dev/sda1,/dev/sdb1 level=1 num-devices=2
ARRAY /dev/md2 devices=/dev/sda2,/dev/sdb2 level=1 num-devices=2
ARRAY /dev/md3 devices=/dev/sda3,/dev/sdb3 level=1 num-devices=2
