On Sun, 30 Aug 2020 at 04:08, Philip Rhoades <phil@pricom.com.au> wrote:
People,

I know this is not strictly a Fedora issue but I only use Fedora so I am
hoping people here can help - maybe we should have a separate mailing
list or forum topic for this sort of hard disk stuff?

Just after a full backup (fortunately) the 7.2TB /home partition
(/dev/sda5) on my email server somehow got corrupted. 

Think about possible hardware issues including: overheating, bad cables, failed disk.
smartmontools can tell you about problems with the drive and run the drive's built-in tests.
Some vendors will issue a warranty return authorization on the strength of linux smartctl
results.
 
After I realised
there was a problem, I unmounted the partition and tried:

   e2fsck -y /dev/sda5

but the process hangs after “Clone multiply-claimed blocks<y>?” and the
disk goes quiet - I could still break out with CTRL-C but I can't get
past this point in the attempted fix process.  So I thought I would just
produce a list of the affected files and then just delete the inodes or
just restore from backup but when I tried:

   debugfs -R "ncheck 187536544" /dev/sda5

it took hours to find nothing but printed screenfulls of:

   ncheck: "Directory block checksum" does not match directory block
while calling ext2_dir_iterate

and there are 1069 inodes to check!

I am guessing that if I just try to delete each of the inodes with:

   debugfs -R "clri <inode>" /dev/sda5

that it would take weeks!  So unless someone can suggest a faster method
of fixing the partition (mainly just as an exercise now) or at least
just working out what is wrong with it, I guess I will just have to
re-create the partition?

I wouldn't spend any time on this drive until I had confidence in the hardware.
 
--
George N. White III