Slightly starting to panic, disc errors

[JonathanM]

11 minutes ago, Jeff in Indy said:

Do I need to wipe the drives and rebuild?

Rebuilding the data disk will result in the lost+found folder being permanently committed, and you will have to deal with that.

Rebuilding parity based on the data disks will put disk2 back like it shows in UD.

 

Which do you want?

[Jeff in Indy]

Well, I KNOW I've got a lost+found in option 1.

 

Using option 2 sounds better, as it MAY help eliminate some or all of the lost+found, or in the worst case, I'm no better off.

 

Are the drives "X"ed out because it has lost parity?  I mean, will rebuilding parity help with making the drives usable again?  I feel like there's something fundamental about the whole thing I'm just not understanding...

[JorgeB]

49 minutes ago, Jeff in Indy said:

It took a while to get it right, but I got Disc 2 in UD and it LOOKS like the data is OK, but I can't figure out how to check the disc or copy the files.

You can copy locally using for example midnight command or the new Dynamix File Manager, you'd need to start the array so:

 

8 hours ago, JorgeB said:

if you want to mount them with the array started you'll need to change both XFS UUIDs in UD settings first.

 

You can also share the UD disk over SMB and copy to another PC, you can check the first couple of posts in the UD support thread for some help with that.

 

49 minutes ago, Jeff in Indy said:

I just want to be able to get the discs to not be disabled. 

If you rebuild now using the old disks you won't get the data that you see in UD, only the one showing in the emulate disks, if that's what you want I can also post instructions.

[trurl]

1 hour ago, JonathanM said:

Rebuilding the data disk will result in the lost+found folder being permanently committed, and you will have to deal with that.

Rebuilding parity based on the data disks will put disk2 back like it shows in UD.

 

Which do you want?

Option 2 here means New Config to get Unraid to accept the disks just as they are and rebuild parity based on their contents.

[Jeff in Indy]

I am using MC to move all of the data from the physical hard drives onto another disc in the array.

 

So here's where I will be when it is done, I need steps to proceed after this:

 

The hard drives will be empty (not zeroed, just empty).  The parity will still have the data from those 2 drives replicated on them, but that data is not needed - all that data has been moved.

 

I'm sure part of the instructions will be to let the parity rebuild to reflect the moved files, but how do I get the drives back to mountable - format it?

 

And in what order do I need to do these steps?

[JorgeB]

Your post is not very clear to me, after moving all the data you want post a screenshot of the GUI main page to see current array status.

[itimpi]

15 hours ago, Jeff in Indy said:

The parity will still have the data from those 2 drives replicated on them

That statement implies you do not understand how parity works.   Parity contains no data per se - it just contains the information that will allow a sector on a failed drive to be reconstructed using the information contents of that sector from the parity drive in conjunction with the corresponding sector from ALL the other array drives.

[trurl]

20 hours ago, trurl said:

Option 2 here means New Config to get Unraid to accept the disks just as they are and rebuild parity based on their contents.

This would have been the better approach since all operations are now using the emulated array, requiring all disks to work to emulate the missing disks, and you have no parity protection.

 

You could have just done New Config, assign the disks back into the array, and rebuild parity. No moving anything anywhere.

 

If you continue with the moving, parity will still be valid since it is maintained realtime and is being kept valid during the moves. But Unraid will want to rebuild the disks when you put them back into the array.

 

Or you could New Config at that point with the now empty drives assigned and rebuild parity. The disks would be empty and I presume mountable since they mounted with UD.

 

You should post screenshots and new diagnostics so we can confirm what your situation is.

[Jeff in Indy]

It's still moving data, but when it's done I'm not sure it will tell the whole story.  My apologies, the story is scattered throughout the thread.  When it's done, I'll post diagnostics, but in the meantime, here's the synopsis:

 

Drive 2 and 8 are unmountable.  I've been assured that the drives are fine, there is another issue.

 

When I did an xfs_repair on the emulalted drive 2, I had 2.2TB that were moved into lost+found.  JorgeB suggested I could reassign the UUID of physical drive 2 and add it to Unassigned Devices, and I might possibly have more intact files that I could move over to another drive or computer.  That's what I'm doing now.  I also, prior to that, moved the emulated files from Drive 8 over to a good drive.

 

So when this move completes, here what I will have:

 

Physical drive 2 will be empty, its files moved to another good drive.

Emulated drive 2 will still show files on it, as it has no idea that I'm secretly having relationships with the physical drive ;-).  Whatever files it thinks I need on drive 2, I don't.

Physical drive 8 will probably still have files on it, but I don't need them, because...

Emulated drive 8 will have already moved those files over.

 

So, both drives will either be empty, or have files I don't care about.  The emulated drives will also either be empty, or have files I don't care about.

 

I will post diags when it completes.  It says 3 1/2 hours, but its estimates has been less than stellar so far...

[trurl]

3 hours ago, Jeff in Indy said:

the story is scattered throughout the thread

I understood it all. You could have just New Config the physical, mountable disks back into the array with all their files intact and rebuilt parity.

 

Instead, you will still have 2 emulated disks after the moves. They will have to be rebuilt, or parity will.

[Jeff in Indy]

I guess I didn't realize what you were talking about.

 

So, assuming there is nothing of value on the Parity drives, I just reintroduce the 2 drives as New Config, and let the parity rebuild?

[trurl]

2 minutes ago, Jeff in Indy said:

assuming there is nothing of value on the Parity drives

Parity drives contain none of your data. They only provide parity bits that allow a disk to be rebuilt from all the other disks.

 

9 hours ago, itimpi said:

Parity contains no data per se - it just contains the information that will allow a sector on a failed drive to be reconstructed using the information contents of that sector from the parity drive in conjunction with the corresponding sector from ALL the other array drives.

 

[trurl]

There is nothing secret or mysterious or even complicated about parity. Parity is basically the same concept wherever it is used in computers and communications. Parity is just an extra bit that allows a missing bit to be calculated from all the other bits.

 

https://wiki.unraid.net/Manual/Overview#Parity-Protected_Array

[Jeff in Indy]

No, I get that.  I was just clarifying that none of the files that are emulated are of any importance to me.

[trurl]

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

[Jeff in Indy]

I CANNOT get the array to stop.   When I do, it keeps saying "Retry unmounting disc share(s)..." in the status bar.  I have rebooted several times, and each time it won't stop the array properly.

 

Is there a way to boot into UnRaid without starting  the array?

[Hoopster]

20 minutes ago, Jeff in Indy said:

Is there a way to boot into UnRaid without starting  the array?

 

In Disk Setting set auto start to No.

 

Edited May 22, 2022 by Hoopster