I think I messed up pretty bad. On my old system, I had 2 identical drive that were assembled with mdadm as a MD RAID 10 with a "far" layout.
When building my new system and migrating the two disks, I had a total brain fart, and instead of doing assemble and scan, I ran the following command:
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdd1 /dev/sde1
When /dev/md0 wouldn't mount, I quickly realized that this was not what I intended, but the damage was done, as mdadm had started the sync. I have stopped mdadm (mdadm --stop /dev/md0), and now I can't mount the drives individually (unknown filesystem type 'linux_raid_member'), and parted doesn't see any filesystem on the partitions of the individual drives.
Is there a way to recover the data from either drive, or did mdadm completely destroy both drives in an unrecoverable way?