i made sh*t can anyone help!?

hi guys i had a raid1 array, and i made shit, could i undo it? it have
filesystem with files :(

# mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb missing
mdadm: /dev/sdb appears to be part of a raid array:
    level=raid1 devices=2 ctime=Wed Mar 16 19:01:50 2011
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
Continue creating array?
Continue creating array? (y/n) y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.