$ sudo mdadm --detail /dev/md0
$ sudo mdadm --assemble --scan --force
$ sudo parted /dev/sda
mktable (msdos) mkpart (primary ext2 0 160GB) set 1 boot on set 1 raid on quit
$ sudo mdadm --re-add /dev/md0 /dev/sda1 --force
$ sudo grub-install /dev/sda