administrator@recovery:~$ sudo mount -o ro /dev/md0 /mnt
[sudo] password for administrator:
mount: wrong fs type, bad option, bad superblock on /dev/md0,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.
administrator@recovery:~$ dmesg | tail
[ 3379.149020] BTRFS info (device md0): disk space caching is enabled
[ 3379.295074] BTRFS error (device md0): parent transid verify failed on 525334003712 wanted 258668 found 256810
[ 3379.298880] BTRFS error (device md0): parent transid verify failed on 525334003712 wanted 258668 found 256810
[ 3379.299242] BTRFS: failed to read tree root on md0
[ 3379.312031] BTRFS: open_ctree failed
[ 3850.713142] BTRFS info (device md0): disk space caching is enabled
[ 3850.828701] BTRFS error (device md0): parent transid verify failed on 525334003712 wanted 258668 found 256810
[ 3850.840725] BTRFS error (device md0): parent transid verify failed on 525334003712 wanted 258668 found 256810
[ 3850.841139] BTRFS: failed to read tree root on md0
[ 3850.852076] BTRFS: open_ctree failed
administrator@recovery:~$