(SOLVED- I think!) XFS Filesystem Repair Failed... (another) Unmountable Disc

[pm1961]

Morning all,

Yesterday I had a double "unmountable file system" error... One array drive and a cache drive.......

 

 

Concentrating on the array drive, after putting the array in maintenance mode, I checked the file system......

 

 

That image doesn't show that it took overnight to reach that stage. If I move that slider fully to the right, it displayed......

 

 

The syslog showed;

 

 

After a reboot it still shows;

 

 

Advice please as to my next move!

 

Kind regards,

 

Paul

 

p.s; attached are before and after diagnostics.... and a smart report for disk5..

 

tower-diagnostics-20200418-1204 After XFS repair.zip tower-diagnostics-20200418-0017 Before XFS repair.zip

Edited April 18, 2020 by pm1961

[JorgeB]

Superblock on the emulated disk is missing/corrupt, that suggest parity wasn't 100% valid.

 

You can see if the actual disk mounts with UD, though since the disk appears to be failing it might be good to clone it with ddrescue first.

[pm1961]

Thanks for your reply...

 

The disk does mount as an UD...... Does that generate other options?

 

Using mc, I can see the full file structure of the disk.

 

As a command line novice,  ddrescue makes me a bit nervous.....

 

Would a blunt solution be to replace the disk and rebuild or are you suggesting the parity might not be up to it?

Edited April 18, 2020 by pm1961
added detail

[JorgeB]

15 minutes ago, pm1961 said:

The disk does mount as an UD...... Does that generate other options?

Yes, either copy everything you can from UD to the array (better after replacing the disable disk) or use ddrecue to clone it to a new disk then rebuild parity based on that, ddrescue is fairly simple to use, more info here.

 

17 minutes ago, pm1961 said:

Would a blunt solution be to replace the disk and rebuild or are you suggesting the parity might not be up to it?

If the emulated disk is unmountable (and not fixable) same will happen if you rebuild to a new disk.

[pm1961]

I didn't have another 4TB disk to hand, so I used a few old disks, also in UD, to copy the files onto........ they all copied off ok....

 

Unraid then allowed me to re-format the disk and insert it back into the array in it's original position and rebuild parity.

 

I did also expect it to rebuild the original contents from parity, but it  hasn't... have I misunderstood?

 

Fortunately, I seem to have all the data off the disk anyway, so I'm now transfering it back into the array.

 

Not having used it before, I'm really impressed with UD and it's ability to mount disks and show them on an SMB network

 

Many thanks for the help!

 

Paul

[JorgeB]

1 hour ago, pm1961 said:

I did also expect it to rebuild the original contents from parity, but it  hasn't... have I misunderstood?

Parity can't help with filesystem corruption, which was the main problem here.