/dev/md0 is comprised of /dev/sdb1 and /dev/sdc1. Due to unknown reason, /dev/md0 was broke last last Friday night. I inactivated it and mounted /dev/sdb1 as /db and started postgresql. Now drake is gluing them back.

umount /db time dd if=/dev/sdb1 bs=1M of=/dev/md0

Don't remount /db from sdb1, or from md0 until the copy is complete. I'll also fsck it just to be sure before mounting. This should take 2.5 hours at the current rate.