[6.12.2] Unmountable: Unsupported or no file system (yet again) (SOLVED)

[elecgnosis]

I was away from home for a week and when I got back, I noticed I had an error in Unraid. Something was wrong with a two-year-old drive.

I shut down the server, checked the cables, and also moved the drive to another slot.

The next startup, it appeared that the drive that I swapped its slot with also had a problem, so I shut down again and shuffled more drives around.

This last startup, the one that I posted diagnostics from, still showed the first problem drive as "Unmountable: Unsupported or no file system" but at least it was the only one that seemed to be bad.

I'm not sure how to proceed. I could just replace it with a hot spare, but I've seen some posts here where people in similar situations were able to repair or restore the file system and even add the drive back to the array.

Diagnostics posted, please advise.

my-diagnostics-20230715-1652.zip

Edited July 30, 2023 by elecgnosis

[elecgnosis]

I found these steps to try, and after mounting the drive, it appears that the data is still there.

However, there's 9TB of data to back up.
I don't have 9TB of free space available on any individual drive in the array, though I guess I could still back it up if I distribute the directories across multiple drives.

Or I could swap the drive and let parity rebuild the data for me.

Unless any of you think there's another route to fixed here that doesn't involve waiting ten days to write 18TB of data, that's the option I'm going to go with.

I will hold on to the troubled drive in case something happens during the parity rebuild.

[elecgnosis]

I ended up doing a new configuration, sacrificing parity. I then spent the last week doing BTRFS scrubs on all of the original array drives, even the first one that had reported errors. All finished without errors.

I'm rebuilding parity now.