破損したCasper-rwファイルをマウント（および修復）するには？

YUMIがMint 19用に作成したcasper-rwを修正する方法についていくつかのチュートリアルを公開しました。ファイルはUSBに作成されましたが、r / wエラーなしでHDDにコピーされました。

$file casper-rw 
casper-rw: Linux rev 1.0 ext2 filesystem data (mounted or unclean), UUID=21054c3a-197b-774e-91ec-7f08ed0eb027, volume name "casper-rw" (errors) (large files)

$sudo mount casper-rw /media/cas
mount: /media/cas: can't read superblock on /dev/loop0.

$dumpe2fs casper-rw | grep superblock 
dumpe2fs 1.44.1 (24-Mar-2018)
  Primary superblock at 0, Group descriptors at 1-1
  Backup superblock at 32768, Group descriptors at 32769-32769
  Backup superblock at 98304, Group descriptors at 98305-98305
  Backup superblock at 163840, Group descriptors at 163841-163841
  Backup superblock at 229376, Group descriptors at 229377-229377
  Backup superblock at 294912, Group descriptors at 294913-294913
  Backup superblock at 819200, Group descriptors at 819201-819201
  Backup superblock at 884736, Group descriptors at 884737-884737

$e2fsck -y -b 98304 casper-rw
  casper-rw was not cleanly unmounted, check forced.
  Pass 1: Checking inodes, blocks, and sizes
  Pass 2: Checking directory structure
  Pass 3: Checking directory connectivity
  Pass 4: Checking reference counts
  Pass 5: Checking group summary information
  Free blocks count wrong for group #0 (31736, counted=6688).
  Fix? yes

  ...

  Directories count wrong for group #30 (0, counted=5).
  Fix? yes

  Free inodes count wrong (1047541, counted=1028864).
  Fix? yes


  casper-rw: ***** FILE SYSTEM WAS MODIFIED *****
  casper-rw: 18688/1047552 files (7.5% non-contiguous), 342826/1046784 blocks

$sudo mount -o sb=98304 casper-rw /media/cas
  mount: /media/cas: can't read superblock on /dev/loop0.