I had a 2-drive RAID-1 array running on ubuntu, which I had forgotten about. The host I was running them on is now dead, leaving me with these two disks. How can I get data off of them? If I dump them- using dd or the such- how can I read that data in a useful format?
All of these steps could be done from a running system but a LiveCD etc. will work just about as well:
Mounting a single disk may or may not "just work" as 3dinfluence said, depending on the
$ mdadm --assemble /dev/md0 /dev/sda1 --run.
With RAID1 you can simply mount the drive as if it were a single drive.
So put the drive in another computer and for instance if the drive was at /dev/sdb run