Parity disk error on rebuild of replacement disk.

[davk60]

I had a power failure and UPS failure during a parity check. After that I had error on one disk (I did not know to save the diagnostics at time) and decidede to replace it. However I got about 4.5% through when it paused with an error. I am not sure what to do.

dkunraid-diagnostics-20211126-1216.zip

[JorgeB]

SMART for parity is showing some issues, but current problem look more power/connection related, power down the server, check/replace cables on parity and then try this, but note that it will only work if parity is still valid:

 

 

-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments and assign any missing disk(s) if needed
-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)
-Stop array
-Unassign disk1
-Start array (in normal mode now), ideally the emulated disk will now mount and contents look correct, if it doesn't you should run a filesystem check on the emulated disk
-If the emulated disk mounts and contents look correct stop the array
-Re-assign disk1 to rebuild and start array to begin.

 

Keep old disk1 intact for now in case it's needed.

[davk60]

Thanks for your help I am learnig a bit. I followed the above and thought all was working but when I returned Disk 1 is listed as umountable again. Whats next?

dkunraid-diagnostics-20211129-0913.zip

[trurl]

20 minutes ago, davk60 said:

followed the above

 

What happened when you got to this?

On 11/26/2021 at 5:25 AM, JorgeB said:

Start array (in normal mode now), ideally the emulated disk will now mount and contents look correct

 

[davk60]

It all seemed to be normal and I backed up all really critical data just incase of a problem. Then I stopped the array, reassigned disk 1 and started the array. I watched the rebuild progress to about 52% but needed to do other things when I came back it seemed to have completed the rebuild but disk1 is still unmountable.

[trurl]

57 minutes ago, davk60 said:

disk1 is still unmountable.

 

On 11/26/2021 at 5:25 AM, JorgeB said:

ideally the emulated disk will now mount and contents look correct

Was the emulated disk mountable?

 

I guess it's moot now since rebuild has already completed. You will have to repair the filesystem.

 

But first, post new diagnostics. Hopefully you didn't reboot after the rebuild.

[davk60]

yesterdays post had the new diagnostics, since then I stoped and started the array to see if disk1 would mount (it didnt) but have not rebooted.

[trurl]

6 minutes ago, davk60 said:

yesterdays post had the new diagnostics

Looks like cache drive is bad, but that wouldn't affect rebuild.

 

Nov 28 19:04:51 dkunraid kernel: md: import_slot: 1 replaced
Nov 28 19:05:03 dkunraid emhttpd: /mnt/disk1 mount error: not mounted
Nov 28 19:05:09 dkunraid kernel: md: recovery thread: recon D1 ...

So, emulated disk1 was unmountable when you began the rebuild. But, as I said, moot now since rebuild has completed. You have to repair the filesystem on the rebuilt disk.

 

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

[davk60]

I am getting a bit confused. I put the system into maintenance mode but when I go to disk1 there is no Check Filesystem Status available.

[trurl]

Since it doesn't know what the filesystem is supposed to be you will have to do it from the command line

 

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

[davk60]

Thank you for your help, the command line repair allowed the disk to rebuild and mount. It seems back to normal.

[trurl]

Check your lost+found share for any files repair couldn't figure out.

[davk60]

I dont see any lost+found share listed in the WebGUI.

[trurl]

There aren't any then