Data rebuild in progress but... drive is still showing "unmountable: not mounted"


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Hello,

 

yesterday I noticed that my disk 2 was disabled and emulated. The health of the drive seems good and no errors so i proceeded to follow these instructions here; https://wiki.unraid.net/Check_Disk_Filesystems

 

It dumped a whole bunch of files into Lost+Found but the disk was still showing disabled.

 

I copied the content of the entire drive to an external hard drive (outside of the array) in an effort of following step 1.5.5 (redoing a drive formatted with XFS).

 

It is currently rebuilding, but i noticed that it's still showing "unmountable: not mounted" while the array is rebuilding with the option to format... 

 

What should i do? will the rebuil fail - do i need to stop, format and then rebuild?

kenny-diagnostics-20211012-0812.zip

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Format is NEVER part of rebuild. Format means write an empty filesystem to this disk. That is what it has always meant in every operating system you have ever used.

 

When you format a disk in the parity array, Unraid treats that write operation just as it does any other write operation, by updating parity. So, after formatting a disk in the parity array, the only thing parity can rebuild is an empty filesystem.

 

 

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Since the emulated disk is unmountable, the result of rebuild will be an unmountable disk. If you repaired it then it bacame unmountable again. Maybe other problems is causing the emulation to be imperfect.

 

Do you have any SMART warnings on the Dashboard page for any disks? Are you seeing any Errors for any disk on the Main page while rebuilding?

 

You shouldn't be ignoring this:

Oct 12 07:15:09 kenny root: Fix Common Problems: Warning: Marvel Hard Drive Controller Installed ** Ignored

 

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Unfortunately the rebuild did not work - it was still showing unmountable.

Luckily I had copied the content of the drive to an offline drive - I simply formatted it and started recopying everything.

 

Now my SMART is reporting re-allocated sectors and rising ... so i guess a bad drive and time to change it out.

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7 minutes ago, flixxx said:

Unfortunately the rebuild did not work - it was still showing unmountable.

 

On 10/12/2021 at 8:31 AM, trurl said:

Since the emulated disk is unmountable, the result of rebuild will be an unmountable disk.

 

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25 minutes ago, flixxx said:

So i suppose the lesson I learnt here is that once a disk is disabled - best to take it off the array and then try to repair the filesystem?

Normally one would start by trying to repair the emulated drive, and then if that works OK rebuilding the disabled drive (either to itself or better a replacement).   That keeps the physical drive intact as long as possible in case you need to try and repair the physical drive as an alternative recovery option.

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Just now, itimpi said:

Normally one would start by trying to repair the emulated drive, and then if that works OK rebuilding the disabled drive (either to itself or better a replacement).   That keeps the physical drive intact as long as possible in case you need to try and repair the physical drive as an alternative recovery option.

 

Thanks for the response - in my case, i ran a filesystem repair due to the errors and suggestions. What that did was create 2,200 folders in the lost+found where some/most are corrupt now.

 

Had I moved the disk out of the array, wouldn't have the drive been emulated until i can get it repaired or replaced therefore avoiding the lost+found scenario above?

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Just now, flixxx said:

 

Had I moved the disk out of the array, wouldn't have the drive been emulated until i can get it repaired or replaced therefore avoiding the lost+found scenario above?

Once a drive is disabled Unraid stops using it until a rebuild (or equivalent) has been performed so no need to remove it from the array at that point.  That is why a repair on the emulated drive is recommended as the first step - it works more often than not and is the fastest and least error prone process if nothing goes wrong.

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Just now, itimpi said:

Once a drive is disabled Unraid stops using it until a rebuild (or equivalent) has been performed so no need to remove it from the array at that point.  That is why a repair on the emulated drive is recommended as the first step - it works more often than not and is the fastest and least error prone process if nothing goes wrong.

hmm ok, i probably did something wrong then. I tried to do the filesystem repair (without the -n) - this whole time i've had an x on the drive yet while i'm still emulated (the new drive should be coming in), i see the lost+found emulated also

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Just now, flixxx said:

hmm ok, i probably did something wrong then. I tried to do the filesystem repair (without the -n) - this whole time i've had an x on the drive yet while i'm still emulated (the new drive should be coming in), i see the lost+found emulated also

If for any reason your parity was not completely valid at that point then this can easily happen as that would mean the emulation would have corruption.

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4 hours ago, flixxx said:

hmm ok, i probably did something wrong then. I tried to do the filesystem repair (without the -n) - this whole time i've had an x on the drive yet while i'm still emulated (the new drive should be coming in), i see the lost+found emulated also

The repair to the emulated drive creates a lost+found folder at the top level of that emulated drive, and, like all top level folders on array or pool, it is a user share named for the folder.

 

4 hours ago, flixxx said:

So i suppose the lesson I learnt here is that once a disk is disabled - best to take it off the array and then try to repair the filesystem?

Disabled and corrupt are independent conditions requiring different solutions.

 

 

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