Unmountable disk present on BTRFS disk

[J89eu]

Hi all

 

I had a disk that went read only so after rebooting the server I now get that it's unmountable.

 

I have attached my diagnostics and also looked through some older posts but most appear to be XFS file systems.

 

I did try some of the things in here:

 

But I got as far as the below where it fails:

root@Atlas:~# mount -o usebackuproot,ro /dev/sdl1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdl1, missing codepage or helper program, or other error.

 

and for the 2nd method

root@Atlas:~# btrfs restore -v /dev/sdl1 /mnt/disk7/restore
No valid Btrfs found on /dev/sdl1
Could not open root, trying backup super
No valid Btrfs found on /dev/sdl1
Could not open root, trying backup super
ERROR: superblock bytenr 274877906944 is larger than device size 536870912
Could not open root, trying backup super

 

Could someone help? it's disk 5.

 

Thanks

atlas-diagnostics-20210206-2202.zip

Edited February 6, 2021 by J89eu

[JorgeB]

It's complaining about an invalid partition:

 

Feb  6 21:30:19 Atlas emhttpd: /mnt/disk5 mount error: Unsupported partition layout

 

This shouldn't happen without reason, and according to the output above it's not just the partition that is damages, it's also missing the btrfs superblock, you can try this as a last resort:

 

btrfs-select-super -s 1 /dev/sdX1

 

Replace X with correct letter, then see if the recovery options work (it will still be unmountable with Unraid due to the invalid partition)

 

 

 

 

 

P.S. also note that most of your other disks are showing previous read errors, and disk2 is lso showing data corruption:

 

Feb  6 21:30:02 Atlas kernel: BTRFS info (device md1): bdev /dev/md1 errs: wr 0, rd 1815, flush 0, corrupt 0, gen 0

Feb  6 21:30:06 Atlas kernel: BTRFS info (device md2): bdev /dev/md2 errs: wr 0, rd 8155, flush 0, corrupt 1036, gen 0

Feb  6 21:30:12 Atlas kernel: BTRFS info (device md3): bdev /dev/md3 errs: wr 0, rd 15394, flush 0, corrupt 0, gen 0

Feb  6 21:30:15 Atlas kernel: BTRFS info (device md4): bdev /dev/md4 errs: wr 0, rd 19748, flush 0, corrupt 0, gen 0

 

 

 

 

[J89eu]

Thanks JorgeB, i just tried that command and got the following output

No valid Btrfs found on /dev/sdl1
Open ctree failed

 

I guess its dead? If I format this volume do I lose any data that was on the disk?

 

Most of the other errors were down to a dodgy cable which has been replaced, not sure what to do aboutt he corruption on disk2, should I try some sort of repair there?

 

Thanks

[JorgeB]

41 minutes ago, J89eu said:

guess its dead?

Looks like the filesystem (or partition) completely disappeared, you're sure it was btrfs like the other disks right?

 

42 minutes ago, J89eu said:

If I format this volume do I lose any data that was on the disk?

Yep.

 

42 minutes ago, J89eu said:

not sure what to do aboutt he corruption on disk2, should I try some sort of repair there?

Run a scrub, any corrupt files will be named in the syslog, and if there are any they need to be deleted/restore from backups.

[J89eu]

So the files can't be emulated by the parity drive? Man...

 

Yes it was definitely btrfs, I've changed nothing really.. It just randomly went read only!

[itimpi]

1 minute ago, J89eu said:

So the files can't be emulated by the parity drive? Man...

 

Parity never emulates 'files' - it emulates disk sectors with no understanding of their contents.  The contents are interpreted at a higher level within the OS.

[JorgeB]

9 minutes ago, J89eu said:

So the files can't be emulated by the parity drive?

Parity can emulate a missing disk, corrupt filesystem is a different problem, though not clear that is the issue here since it looks more like the partition/superblock disappeared, you can try unassigning that disk and see if Unraid can emulat it, the partition would be re-created.

[J89eu]

Ok I will try that once this btrfs scrub runs on disk2. Currently showing 19 uncorrectable errors...

[J89eu]

Ok well, formatted Disk5 in the end, I have no idea what was on that disk, nothing seems broken... Probably movies/TV but is there any way to work it out?

 

Also regarding the uncorrectable errors on Disk2, I ended up with around 1200 but not sure what can be done about that? I guess the disk is just dying?

[JorgeB]

53 minutes ago, J89eu said:

I ended up with around 1200 but not sure what can be done about that?

 

On 2/7/2021 at 12:08 PM, JorgeB said:

corrupt files will be named in the syslog, and if there are any they need to be deleted/restore from backups.

 

53 minutes ago, J89eu said:

I guess the disk is just dying?

No necessarily a disk problem, could be other hardware issue, run a scrub on the other disks, if more corruption is found it's not likely the disk.