I had the same problem when converting from one disk to a RAID-1 setup.
I added a break=mount and tried to start the arrays with "mdadm -A -s", but that didn't work.
The default configuration has a line "DEVICE partitions" in /etc/mdadm/mdadm.conf. This apparently doesn't work.
(All my partitions are listed in /proc/partitions and the major/minor numbers match up to those in /dev)
Adding the ARRAY lines to mdadm.conf and regenerating the initrd image worked for me.
I'm using gutsy 7.10 x86_64 with Linux image 2.6.22-14-generic (all updates installed).
I had the same problem when converting from one disk to a RAID-1 setup.
I added a break=mount and tried to start the arrays with "mdadm -A -s", but that didn't work.
The default configuration has a line "DEVICE partitions" in /etc/mdadm/ mdadm.conf. This apparently doesn't work.
(All my partitions are listed in /proc/partitions and the major/minor numbers match up to those in /dev)
Adding the ARRAY lines to mdadm.conf and regenerating the initrd image worked for me.
I'm using gutsy 7.10 x86_64 with Linux image 2.6.22-14-generic (all updates installed).