So, I swapped out one of the older/smaller disks in my array -- disk #5 of 6 -- for a larger one, and after starting the machine up, and found that one of the other disks (disk 4) was also offline.  Because two disks were missing (#4 & #5), Unraid wouldn't let me rebuild disk 5.

 

I shut the server down to check the cables and after powering back on found that disk 4 was now reporting "Unmountable: Unsupported or no file system" (which I believe was different from the initial error). It was, however, now giving me the option to rebuild disk 5 which, for better or worse, I did.

 

Rebooted again, disk 4 was still offline, running emulated. Restarted the array in maintenance mode and ran the filesystem check from the GUI. 

It ran for ~3 hours, starting with "Phase 1 - find and verify superblock... couldn't verify primary superblock - not enough secondary superblocks with matching geometry !!!"

and ending with

"Sorry, could not find valid secondary superblock Exiting now."

 

Diagnostics are attached from after the filesystem check failed (though I also have diagnostics from earlier). 

 

Any advice on what to do next would be greatly appreciated. Thanks.

tower-diagnostics-20240111-2106 - post-fix attempt.zip

Diags are after rebooting so we can't see what happened, but you also need to check filesystem on disk5, as for disk4, see if actual disks mounts with UD.

To check Disk 4 with UD, I need to stop the array and remove the drive from the array (set Disk 4 to "no disk")?

 

Also, attached is the output of the disk 5 filesystem check.

Disk 5 filesystem check.txt

Just now, GozuTashoya said:

To check Disk 4 with UD, I need to stop the array and remove the drive from the array (set Disk 4 to "no disk")?

Correct.

 

1 minute ago, GozuTashoya said:

Also, attached is the output of the disk 5 filesystem check.

You need to run it without -n or nothing will be done, and if it asks for -L use it.

Disk 4 mounted successfully as UD. Ran filesystem check (attached). Safe to go ahead and hit "run with correct flag"?

 

Ran Disk 5 filesystem check with -n, and it fixed stuff. Running it again had more items, so I re-ran it with -n. Logs attached.

Disk 4 filesystem check.txt Disk 5 filesystem check (3rd run with -n flag removed).txt

Edited January 12, 20242 yr by GozuTashoya

Is it safe to start the array and use Unraid as usual while Disk 4 is removed from the array and just hanging out as an unassigned device?

Try and repair the filesystem on disk4 with UD.

 

In the meantime you can start the array with disk4 in UD, it will be unprotected of course, since there's a disabled disk.

8 hours ago, JorgeB said:

Try and repair the filesystem on disk4 with UD.

 

In the meantime you can start the array with disk4 in UD, it will be unprotected of course, since there's a disabled disk.

Disk 4 now reports "No file system corruption detected!" (Results attached in case it helps.)

 

Next step is to re-add Disk 4 to the array?

Disk 4 filesystem check - UD 2024-01-13.txt

Edited January 13, 20242 yr by GozuTashoya

Mount old disk4 with UD and confirm it mounts and contents look OK, if yes you then have two main options:

 

1 - do a new config with old disk4 and the remaining disks and re-sync parity

2 - use a spare disk to rebuild disk4 and then copy the data from the old one to the array

5 hours ago, JorgeB said:

Mount old disk4 with UD and confirm it mounts and contents look OK, if yes you then have two main options:

 

1 - do a new config with old disk4 and the remaining disks and re-sync parity

2 - use a spare disk to rebuild disk4 and then copy the data from the old one to the array

Just to clarify my earlier comment, Old Disk 4 (Physical, as UD) is the one that reports no file system corruption. Disk 4 (emulated, in the array) still fails filesystem check.

 

With that in mind, is Option 2 still an option, or would rebuilding result in the same broken/unusable filesystem?

 

Anyway, that said, Old Disk 4 (physical) does mount fine and the contents indeed look OK.

 

Assuming I want to go with Option 1, do the steps look like this?

1. Stop array.

2. Tools -> New Config.

3. Choose "All" for Preserve Current Assignments.

4. Click "Yes i want to do this" checkbox. Click "Apply".

5. Main Tab -> Change Disk 4 (currently unassigned) to Old Disk 4 Drive (physical).

6. Start array.

7. Let Unraid create new parity sync. (Array should be usable, if slowish?)

And will those steps preserve the data on Old Disk 4 (physical), almost as though the whole filesystem corruption didn't happen? I.e., Old Disk 4 won't need be formatted/precleared?

19 hours ago, GozuTashoya said:

With that in mind, is Option 2 still an option, or would rebuilding result in the same broken/unusable filesystem?

The disk in the array would need to be formatted, then you'd copy the data from the old disk4 mounted in UD.

 

19 hours ago, GozuTashoya said:

• Stop array.

• Tools -> New Config.

• Choose "All" for Preserve Current Assignments.

• Click "Yes i want to do this" checkbox. Click "Apply".

• Main Tab -> Change Disk 4 (currently unassigned) to Old Disk 4 Drive (physical).

• Start array.

• Let Unraid create new parity sync. (Array should be usable, if slowish?)

Correct.

 

19 hours ago, GozuTashoya said:

And will those steps preserve the data on Old Disk 4 (physical), almost as though the whole filesystem corruption didn't happen? I.e., Old Disk 4 won't need be formatted/precleared?

Correct, it cannot be precleared/format or the data there will be gone.