fsck shows thousands of group descriptor errors on ext4 volume.
This data drive disappeared from the system two days ago. I've had problems with drives in that bay when rebooting into Ubuntu from Windows and so I put it in a different bay and it seemed to be working well after reboot. Today when I rebooted into Ubuntu from Windows, I saw Deluge showing errors and unable to recheck files cleanly. Running fsck -a gave
fsck from util-linux-ng 2.17.2
/dev/sdc1: One or more block group descriptor checksums are invalid. FIXED.
/dev/sdc1: Group descriptor 0 checksum is invalid.
/dev/sdc1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options)
But running fsck manually, I get
One or more block group descriptor checksums are invalid. Fix<y>? Y
THen lots of:
Group descriptor 888 checksum is invalid. FIXED.
Group descriptor 889 checksum is invalid. FIXED.
Group descriptor 890 checksum is invalid. FIXED.
/dev/sdc1 contains a file system with errors, 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 #335 (32768, counted=5759).