How to make GRUB2 detect and boot Ubuntu on a RAID 1?

Question

grub 2 is unable to detect /dev/md1 which is a raid 1 drive on my computer.

When I press c in grub menu and run ls I get a list of all the drives but don't see md1 for booting Ubuntu which is on md1_p1.

This is the config I'm using in the grub2 40_custom file.

    menuentry "Ubuntu 12.10 uuid" {
        insmod ext2
        insmod mdraid
        set root='(md1,1)'
        search --no-floppy --fs-uuid --set=root 23451bea-fd08-cff7-9289-9f9aa51f8599
        linux /boot/vmlinuz-3.5.0-17-generic root=UUID=23451bea-fd08-cff7-9289-9f9aa51f8599 ro
        initrd /boot/initrd.img-3.5.0-17-generic
}

I'm able to load linux installed on other partition but unable to start 12.10 which I've just installed on a raid 1 ext4 fs.

Solution

I was able to fix the issue using boot-repair using live cd. I followed the following steps

1. Start ubuntu using live CD
2. Install mdadm sudo apt-get install mdadm
3. Assemble the array sudo mdadm --assemble --scan
4. Install boot-repair sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update sudo apt-get install -y boot-repair && boot-repair
5. Using advanced options in boot-repair I was able to select /dev/md1 as my operating system (this is the RAID where my ubuntu was installed earlier)
6. Reboot and select Ubuntu on RAID 1

This way boot-repair purged the previous installation of grub and installed a new one and I think that's how the problem was solved as this new version was able to detect the RAID 1 drive.