Can't get parity drive up and running

[dcruff]

I have three 14TB drives, with one of them acting as a parity drive.  Since I'm about 90 percent full on the two data disks I ordered a new 16TB drive.  I didn't realize at the time that I needed to make sure that the new drive was no bigger than the parity drive, so I attached the new 16TB drive and formatted it xfs while in 'unassigned devices'.   After I realized my error, I decided to use the new 16TB drive as the parity drive (and forfeit the extra 2 TB).

I stopped the array and removed the original parity drive (14TB).  Then I attached the new drive (16TB) using the same cables as the former drive (14TB), but Unraid still just showed it as a formatted drive in the Unassigned section, but I could not find any way to assign it as the parity drive.  Then, while consulting ChatGPT, I did a 'Clear disk' on the new 16TB drive to remove the formatting so that Unraid would see the drive as a new unformatted drive and prompt me to assign it as the parity drive and go through it's normal process of setting it up for the parity drive.  No such options presented themselves and I could not find any other way to assign it as such.
So, I then stopped the array and put the original parity drive back in and took the new drive out so that I could start over again.
All of this time, each time I restarted Unraid, my array (now only two drives) was intact with all of the data.
Now with the old drive back in its' original bay and cables, it just shows as 'formatted' and I can't find any options to add it as the parity drive, back to where I started.

Now I have an unprotected array.
I would love some suggestions as to how I can get my parity back.

[dcruff]

Actually, I may have figured it out.  I put the new unformatted 16TB disk back in, started up unraid and then stopped the array.  From there, I was able to see an option to assign the drive to the array.  I believe that it is now rebuilding the parity device (new 16TB disk).  I'll update when it is completed.  

[dcruff]

I finally figured it out, with the help of ChatGPT,  It was a lengthy process to get everything working the way I wanted.

The New 16TB drive took about 22 hours to set itself up as the new parity drive once I cleared it.  I had to take the array down, then in the drive screen, I picked the top option to assign the new drive as 'Parity 1'.  It was not intuitive because the option didn't show up until I selected that drive space and a drop down showed my unassigned drive, which I selected.
After the parity drive was set up, I added my 14TB disk (previous parity disk) and added it to the array.  It took another 18 hours to clear and prepare the disk.  After that, I had to format the drive and then it was ready.

Now everything works.

[dcruff]

Well now I have another problem - the 14TB drive that I added to the array (Disk 3) is now showing 'Unmountable: Unsupported or No File System'.  I don't have any errors that I can find, and files that I stored to that drive are now non-existent.  I rebooted Unraid and nothing changes.  The file system is listed as XFS. with 470 READS, 0 WRITES, and 0 ERRORS.

The movie files that I added are now where to be found, assumable being stored on Disk 3.  Shouldn't there be some kind of recovery available since I have a parity drive associated with my array?

[itimpi]

It is not clear to me why you think there would be any files on a drive you have just added?   Have I missed something?    
 

Normally when you add a new drive to the array Unraid Clears it (I.e. sets it to be all zeroes) to avoid invalidating parity.    When that completes you then format the drive to create an empty file system and make it ready for use.   This is the process documented here for adding drives in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page.

[dcruff]

3 hours ago, itimpi said:

It is not clear to me why you think there would be any files on a drive you have just added?   Have I missed something?    
 

Normally when you add a new drive to the array Unraid Clears it (I.e. sets it to be all zeroes) to avoid invalidating parity.    When that completes you then format the drive to create an empty file system and make it ready for use.   This is the process documented here for adding drives in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page.

After I successfully added the 14TB drive to the array (or so I thought), UNRAID showed me that I had a new 14TB of available, usable space.  I then went about my business adding movie files, and other stuff to the array - a couple of hundred GB of data.  I did this yesterday.  Then today, the drive is inaccessible and I don't know why.  My Emby Server still shows the movies that I added to the library, but now shows that all of the data is missing.
What really concerns me is why there is no way of reclaiming that data when it is in a parity-protected drive array.  What's the reason for the parity drive?

 

[itimpi]

If the drive was previously showing as mountable then have you followed the procedure documented here for handling unmountable disks in the online documentation accessible via the Manual link at the bottom of the Unraid GUI.?   In addition every forum page has a DOCS link at the top and a Documentation link at the bottom.

 

You should post your system's diagnostics zip file in your next post in this thread to get more informed feedback.  It is always a good idea to post this if your question might involve us seeing how you have things set up or to look at recent logs.

[dcruff]

Yep, the drive was showing as mountable, and I mounted it, formatted it, and started using it.  Loaded files, which got stored to it because my other two drives were getting full.  Then the next day, they are unmountable and unusable.  I didn't put much new data on it, be I'm very concerned that this could happen and makes me nervous in case it happened to one of my full drives.  I went looking through the Alerts, Warnings, and Notices to see if there was any indication of a problem.  None that I could see.
I have seen that there are options to try to repair a faulty structure on a disk, but I would like to know what happened and how it can happen again.  Realize that I have been using this particular disk in this UNRAID computer as the Parity Drive for over a year with absolutely no problems.  But now that it's been cleared, re-mounted, formatted, and data stored on it, it is having problems.
 

embyserver-diagnostics-20240409-0707.zip

[JorgeB]

Apr  8 13:36:40 EmbyServer kernel: XFS (md3p1): Corruption detected. Unmount and run xfs_repair
Apr  8 13:36:40 EmbyServer kernel: XFS (md3p1): log has mismatched uuid - can't recover

 

Check filesystem on that disk, run it without -n and if it asks for -L use it.

[dcruff]

That does appear to have fixed the issue, as my files appear to be intact (what few of them had actually been written to the drive).  I'll watch it to see if this reoccurs.  What scares me is that it happened within a day of getting the drive up and running as an array data drive instead of the parity drive.

Thanks, the chkdsk function in the GUI was painless and it was necessary to know about removing the -n.

[JorgeB]

34 minutes ago, dcruff said:

What scares me is that it happened within a day of getting the drive up and running as an array data drive instead of the parity drive.

Was the parity drive cleared before being assigned to the array? Also did you already have 3 data disks before?

[dcruff]

The parity drive was cleared and formatted as part of the process of setting it up as a data drive.  I only had 2 data disks before, so when I replaced the 14TB parity disk with a new 16 TB disk, I added that former parity drive (14TB) to the data array, making it a drive array of 1 Parity (16TB) and now 3 Data disks (14TB each).

[JorgeB]

1 hour ago, dcruff said:

The parity drive was cleared and formatted as part of the process of setting it up as a data drive. 

OK, in that case it has nothing to do with being parity before, hopefully just a one time thing, but if it happens again I would suspect an underlying hardware issue.