1e2fsck external journal 2../e2fsck/e2fsck: Filesystem has unsupported feature(s) while trying to open test.img 3 4The superblock could not be read or does not describe a valid ext2/ext3/ext4 5filesystem. If the device is valid and it really contains an ext2/ext3/ext4 6filesystem (and not swap or ufs or something else), then the superblock 7is corrupt, and you might try running e2fsck with an alternate superblock: 8 e2fsck -b 8193 <device> 9 or 10 e2fsck -b 32768 <device> 11 12Exit status is 8 13dumpe2fs external journal 14Filesystem volume name: <none> 15Last mounted on: <not available> 16Filesystem magic number: 0xEF53 17Filesystem revision #: 1 (dynamic) 18Filesystem features: journal_dev metadata_csum 19Default mount options: user_xattr acl block_validity 20Filesystem state: clean 21Errors behavior: Continue 22Filesystem OS type: Linux 23Inode count: 0 24Block count: 2048 25Reserved block count: 0 26Free blocks: 0 27Free inodes: 0 28First block: 1 29Block size: 1024 30Fragment size: 1024 31Blocks per group: 8192 32Fragments per group: 8192 33Inodes per group: 0 34Inode blocks per group: 0 35Mount count: 0 36Check interval: 0 (<none>) 37Reserved blocks uid: 0 38Reserved blocks gid: 0 39First inode: 11 40Inode size: 256 41Required extra isize: 28 42Desired extra isize: 28 43Default directory hash: half_md4 44Checksum type: crc32c 45Journal features: journal_64bit journal_checksum_v3 46Journal size: 2048k 47Journal length: 2048 48Journal first block: 3 49Journal sequence: 0x00000003 50Journal start: 0 51Journal checksum type: crc32c 52Journal checksum: 0x661e816f 53Journal users: 117f752e-f27d-4f6f-a652-072586a29b82 54