Replacing Data Drive

[ExitusLSU]

One of my data drives died over the weekend, so I replaced it with a new 4TB drive (as big as my parity).  I followed the directions at https://lime-technology.com/wiki/Replacing_a_Data_Drive and all seemed well, though I did not see a checkbox as listed in step 9 (Put a check in the Yes, I'm sure checkbox (next to the information indicating the drive will be rebuilt), and click the Start button).  I started the array and it started running a parity sync/data rebuild.  I let it run over night and it completed fine.  Unfortunately, the drive shows that it is only filled with a few gigabytes, not filled up like the previous drive.  Am I fooked?  Did I just redo my parity, cleaning any recovery of the dead drive?

 

I still have the old drive.  If I can get it up and running, is there a way to rebuild the parity based on it?

 

I'm running Unraid 6.5.2.

 

Thanks.

Edited August 7, 2018 by ExitusLSU

[trurl]

Hope you didn't agree to format anything. Did you?

[ExitusLSU]

I formatted the drive to xfs before starting the parity sync/data rebuild.  I fooked myself didn't I??

[itimpi]

5 minutes ago, ExitusLSU said:

I formatted the drive to xfs before starting the parity sync/data rebuild.  I fooked myself didn't I??

Yes.   Doing a format instructs unRAID to create an empty file system on the disk and update parity to reflect this.    You should have done the rebuild without the format.   When you try to do a format you should have gotten a warning that doing it will erase any data on the disk - what change to the wording of that warning would have stopped you doing the format?

 

If you have backups (you should have for anything important) then restore from that.   If not then at this point your best way forward is probably to see if the old disk is not truly dead, and if it is not mount it using the ‘unassigned Devices plugin to copy off it as much data as possible.

Edited August 7, 2018 by itimpi

[ExitusLSU]

5 minutes ago, itimpi said:

Yes.   Doing a format instructs unRAID to create an empty file system on the disk and update parity to reflect this.    You should have done the rebuild without the format.   When you try to do a format you should have gotten a warning that doing it will erase any data on the disk - what change to the wording of that warning would have stopped you doing the format?

 

? I'm not sure... I just thought the drive had to be formatted.

 

Ugh... I don't even know what I lost now.  Years of family pictures and videos gone because I didn't following the damn instructions exactly.

 

Gotcha, thanks.  I can't get the old drive up and running... and unraid was my backup.  Ugh...

Edited August 7, 2018 by ExitusLSU

[ExitusLSU]

Looks like most of my family videos and pictures are still on the array, might just be missing some of my tv shows and movies.

 

Anyone know if it's possible to recover a bad drive?  I loaded up Mint and plugged the bad drive up to a external port and got an error mounting /dev/sdc1 to mint, wrong fs type, bad option, bad superblock.

 

 

[pwm]

Note that formatting the drive doesn't overwrite all of the surface.

 

 

So some data may be possible to recover by getting a data recovery program that scans the disk surface looking for the signatures of directories etc. and tries to locate data.

 

Depending on the state of the old drive, it might be possible to recover some files from it.

And even the new drive - despite the reformat - will after the rebuild have file data on the disk surface even if the reformat destroyed the index information.

 

How much you can recover is almost impossible to guess. But some of the recovery programs allows you to download and test them and they will then give you some form of indication of how much the program can recover if you pay the full license.

[trurl]

9 hours ago, ExitusLSU said:

I just thought the drive had to be formatted.

 

Many people have a very vague idea about the meaning of "format". They think it just means something like "prepare this drive for use". It actually means "write an empty filesystem to this disk". That is what it has always meant in every operating system you have ever used. Like all write operations, unRAID updates parity so it is in sync with the format. So after the format of a disk in the array, rebuilding the disk from parity results in a formatted disk.

[JorgeB]

Surprising to me how this keeps happening even with the warning added on the latest releases:

 

 

 

 

[ExitusLSU]

7 hours ago, johnnie.black said:

Surprising to me how this keeps happening even with the warning added on the latest releases:

 

 

 

 

 

Yeah, I know.  Lesson learned... I took the format as "prepping the drive" to have the parity data written to it, not tell Unraid that I'm deleting everything on that particular drive and then to update parity.  Luckily, it looks like most of my important files are still around, so not a total loss.  I will definitely be backing the files up onto something else.

 

I'm hoping I can mess with the "broken" drive and get some files off of it.  When I plug the drive up to an external dock, it powers on and spins up, but Windows won't mount it, it just throws errors that show up in the event viewer.  I plug it up in Linux, I can see the drive, I can even select it, but then it throws an errors saying it can't mount.  I'm hoping I can get something like UFS Explorer and get access to the data.?

[ExitusLSU]

Success!  I was able to get the data off my "dead" drive using UFS Explorer.

 

Next time I need to replace a drive, I will not format the drive.?