I have one 18TB drive in XFS format as backup and from time to time I run rsync command to backup important data from my array.

Today I can not mount this drive, each time I see

Quote

Device '/dev/sdf' failed to mount. Check the syslog for details.

In syslog

Nov  4 22:16:03 BlackBox unassigned.devices: Mounting partition 'sdf1' at mountpoint '/mnt/disks/backup'...
Nov  4 22:16:03 BlackBox unassigned.devices: Mount cmd: /sbin/mount -t 'xfs' -o rw,relatime '/dev/sdf1' '/mnt/disks/backup'
Nov  4 22:16:03 BlackBox kernel: XFS (sdf1): Mounting V5 Filesystem
Nov  4 22:16:03 BlackBox kernel: XFS (sdf1): Log inconsistent (didn't find previous header)
Nov  4 22:16:03 BlackBox kernel: XFS (sdf1): failed to find log head
Nov  4 22:16:03 BlackBox kernel: XFS (sdf1): log mount/recovery failed: error -117
Nov  4 22:16:03 BlackBox kernel: XFS (sdf1): log mount failed
Nov  4 22:16:05 BlackBox unassigned.devices: Mount of 'sdf1' failed: 'mount: /mnt/disks/backup: mount(2) system call failed: Structure needs cleaning.        dmesg(1) may have more information after failed mount system call. '
Nov  4 22:16:05 BlackBox unassigned.devices: Partition 'backup' cannot be mounted.

I have tried manually run next command:  

xfs_repair - n /dev/sdf1 

and then  

xfs_repair /dev/sdf1

Output

Phase 1 - find and verify superblock...
Phase 2 - using internal log
        - zero log...
Log inconsistent (didn't find previous header)
failed to find log head
zero_log: cannot find log head/tail (xlog_find_tail=5)
ERROR: The log head and/or tail cannot be discovered. Attempt to mount the
filesystem to replay the log or use the -L option to destroy the log and
attempt a repair.

 

What should I do and how to solve it? And why did it happen? 

Maybe easiest would be - just format this drive and create FS from scratch? How would unraid works with EXT4? Because honestly on EXT4 I did not have such issues.

 

Ok, problem solved:

• executed xfs_repair -L /dev/sdf1
• repair successfully finished and disk is empty
• formatted drive to BTRFS and forgot about XFS on non-Array device.