Tried a bunch of stuff and google-fu exhausted.
# parted /dev/sdai GNU Parted 2.1 Using /dev/sdai Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Model: ATA WDC WD60EFRX-68M (scsi) Disk /dev/sdai: 6001GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 6001GB 6001GB ext2 primary #lsblk dai 66:32 0 5.5T 0 disk └─sdai1 66:33 0 5.5T 0 part #umount /dev/sdai1 /dev/backup1 umount: /dev/sdai1: not mounted umount: /backup1/: not mounted # mount -t ext4 /dev/sdai1 /backup1/ mount: /dev/sdai1 already mounted or /backup1/ busy # mount -t auto /dev/sdai1 /backup1/ mount: unknown filesystem type 'linux_raid_member' #mount /dev/sdai1 /backup1/ mount: unknown filesystem type 'linux_raid_member' # mdadm --create --verbose /dev/md5 --level=stripe --raid-devices=2 /dev/sdai1 /dev/sdaj1 mdadm: chunk size defaults to 512K mdadm: /dev/sdai1 appears to contain an ext2fs file system size=1565553664K mtime=Wed Dec 31 16:00:00 1969 mdadm: /dev/sdai1 appears to be part of a raid array: level=raid0 devices=2 ctime=Wed Jul 13 13:24:57 2016 mdadm: /dev/sdaj1 appears to contain an ext2fs file system size=1565553664K mtime=Wed Dec 31 16:00:00 1969 mdadm: /dev/sdaj1 appears to be part of a raid array: level=raid0 devices=2 ctime=Wed Jul 13 13:24:57 2016 #lsblk sdai 66:32 0 5.5T 0 disk └─sdai1 66:33 0 5.5T 0 part └─md5 9:5 0 10.9T 0 raid0 sdaj 66:48 0 5.5T 0 disk └─sdaj1 66:49 0 5.5T 0 part └─md5 9:5 0 10.9T 0 raid0 # mount /dev/md5 /backup1/ mount: you must specify the filesystem type # mount -t ext2 /dev/md5 /backup1/ mount: wrong fs type, bad option, bad superblock on /dev/md5, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so # mount -t ext2fs /dev/md5 /backup1/ mount: unknown filesystem type 'ext2fs' # mount -t auto /dev/md5 /backup1/ mount: you must specify the filesystem type [link] [comments]