[Solved] Unmountable disk after data rebuild

[gerhard911]

I have replaced / rebuilt a data disk three times now and after each parity sync which appears to run successfully I end up with a message after starting the array that the disk is unmountable with no file system.

 

This all started with data disk5 showing a lot of read errors. It was an older 8TB HGST drive so I swapped in a newer Segate 8TB and synched parity. That rebuild worked fine but the new drive also experienced read errors.

 

Having planned to increase this server's capacity anyway, I purchased a pair of Segate 14TB drives and replaced the 10TB parity drive with a 14TB drive and rebuilt parity. That appeared to run without issues so I swapped out the Seagate 8TB disk5 for the previous parity 10TB drive and rebuilt data. That resulted in my first unmountable disk.

 

I stopped the array, unassigned the 10TB disk and moved it to a previously unused SATA port. Restart the server, assign the 10TB disk to disk5 and rebuild data. Again, after appearing to rebuild successfully I end up with an unmountable drive.

 

So I swap the SATA port & cable between disk5 and a cache pool drive and rebuild a third time. Same result with disk5 (unmountable) but now the cache drive is also unmountable.

 

I downloaded diagnostics after each step and am attaching those .zip files.  I also took screen captures of the Main page after each step in the parity sync / restart process and will attach those .jpg files.

 

I realize now I should have probably saved the original 10TB parity drive intact and rebuilt disk5 on the other new 14TB. I am concerned that the unmountable disk issue is due to something happening with the 14TB parity drive swap. So I am tempted to rebuild parity with the original 8TB drive but need to know if I can trust the original 8TB disk5's data.

 

Is there a way I can check that drive to see if it's data is intact? I have the Unassigned Devices plugin but don't know if / how it can be used to do this.

 

Many thanks for any advice or assistance.

unraid2-diagnostics-Parity sync done.zip unraid2-diagnostics-Parity sync stopped.zip unraid2-diagnostics-Post parity sync unmountable.zip

[itimpi]

Handling of ‘unmountable’ disks is covered here in the online documentation accessible via the ‘Manual’ link at the bottom of the Unraid GUI.

 

Have you run a file system check on the drive?    
 

Was the drive showing as unmountable before the rebuild (since a rebuild does not clear ‘unmountable’ state`).

[trurl]

Rebuilding an unmountable disk will just result in an unmountable disk. You have to repair the filesystem as explained in the link given above.

[XAPBob]

On 12/11/2020 at 5:28 PM, itimpi said:

Handling of ‘unmountable’ disks is covered here in the online documentation accessible via the ‘Manual’ link at the bottom of the Unraid GUI.

 

Have you run a file system check on the drive?    
 

Was the drive showing as unmountable before the rebuild (since a rebuild does not clear ‘unmountable’ state`).

Thanks for the link - hopefully this third iteration of ifs repair will do it's job on my system.

[zefie]

On 12/11/2020 at 12:28 PM, itimpi said:

Handling of ‘unmountable’ disks is covered here in the online documentation accessible via the ‘Manual’ link at the bottom of the Unraid GUI.

 

Have you run a file system check on the drive?    
 

Was the drive showing as unmountable before the rebuild (since a rebuild does not clear ‘unmountable’ state`).

Hi, I am having this problem, but the wiki page was removed.
Here is what happened:


1) a few disks are USB
2) accidently unpowered external USB hub while Unraid was running
3) Unraid got upset
4) repowered hub and rebooted
5) 2 disks are "Unmountable"
6) did xfs_repair on sdX1 for both drives, xfs_repair was successful
7) Unraid still says unmountable
8 )  reboot
9) Unraid still says unmountable
10) stop array, start array with those two disks as "none"
11) stop array, start array with the disks configured again
12) Finishes, Unraid still says unmountable, but changed from red X to blue square
13) Parity wants to restore, allow it. 
14) Parity restore finishes, Unraid still says unmountable

Update: Apparently I was most of the way there. To finish:
15) xfs_repair the drives again after parity restore
16) reboot
 

Edited November 30, 2022 by zefie
fixed

[trurl]

1 hour ago, zefie said:

the wiki page was removed

Links in old posts often don't work.

 

Not hard to find in the Documentation though.

 

https://wiki.unraid.net/Manual/Storage_Management#Drive_shows_as_unmountable

 

Repairing the sdX1 partition is incorrect for disks in the parity array. You must repair the md# device instead or you will invalidate parity. Since you rebuilt from parity anyway the disks were restored as they were before the repair.

 

If you then repaired the sdX1 partiition again then you may have invalidated parity. You must now run a non-correcting parity check.

 

Anybody else with a similar problem and finding this thread, please ask for help and post your diagnostics.

 

1 hour ago, zefie said:

a few disks are USB

NOT recommended for array or pool disks for many reasons.

[trurl]

@zefie

17 minutes ago, trurl said:

If you then repaired the sdX1 partiition again then you may have invalidated parity. You must now run a non-correcting parity check.

 

[zefie]

Yeah, I forgot step 17: Parity check with "Write corrections to parity" checked