I replaced a failed drive 3 with a new drive.  After starting the array, the data rebuild started, but the drive also showed it was unformatted.  Thinking it needed to have the file system initialized in order for the data to be rebuilt from parity, I formatted to new drive.

 

The data rebuild then proceeded following the format of drive 3, but now drive stats show no data on drive 3.  Prior to the format, drive 3 showed data present, even when starting the array with no drive in slot 3 (due to the parity drive).

 

I stopped the array shortly after the format completed fearing the worse.  The array was still in a data rebuild showing it would take over a day to complete.  Did I just loose the data on drive 3 by 'formatting' the new drive?  Should I re-start the array and let the 'data-rebuild' complete with the new drive 3 showing empty and the data will then appear on drive 3 after it is completed?

 

If I indeed lost the parity information for drive 3 by using the 'format' command, is there any way to recover the data?

 

Drive 3 has an orange ball indicating invalid data content as expected since I did not let the data rebuild complete following the drive format.

I replaced a failed drive 3 with a new drive.  After starting the array, the data rebuild started, but the drive also showed it was unformatted.  Thinking it needed to have the file system initialized in order for the data to be rebuilt from parity, I formatted to new drive.

That was a mistake.  It should not have needed formatting if replacing an existing disk.

The data rebuild then proceeded following the format of drive 3, but now drive stats show no data on drive 3.  Prior to the format, drive 3 showed data present, even when starting the array with no drive in slot 3 (due to the parity drive).

That is because you re-formatted the drive.

I stopped the array shortly after the format completed fearing the worse.  The array was still in a data rebuild showing it would take over a day to complete.  Did I just loose the data on drive 3 by 'formatting' the new drive?

Yes, but you might be able to get it back by running reiserfsck with the --rebuild-tree --scan-entire-partition options.

Should I re-start the array and let the 'data-rebuild' complete with the new drive 3 showing empty and the data will then appear on drive 3 after it is completed?

It will not re-appear on its own.

If I indeed lost the parity information for drive 3 by using the 'format' command, is there any way to recover the data?

not a huge chance, but some chance.  Contact Tom @ lime-technology , point him to this thread.  It will not be trivial to get your data back. 

 

first, I think you need to supply a copy of your syslog, a screen print of the unRAID screen, and the version of unRAID you are running.

Drive 3 has an orange ball indicating invalid data content as expected since I did not let the data rebuild complete following the drive format.

Again, I have no idea of the current state.  At the least you'll need to know if the disk has a partition starting on sector 63? or sector 64? or is it a GPT partition (the disk is > 2.2TB)

 

Then, you'll need to see if the partition can be found on the emulated disk on /dev/md3 or on the physical disk /dev/sdX1

 

Lastly, you'll want to see what can be recovered via reiserfsck --rebuild-tree --scan-entire-partition once you locate your file-system.

... Did I just loose the data on drive 3 by 'formatting' the new drive?

 

Yes.

 

Unless the reiserfsck with the --rebuild-tree --scan-entire-partition  that Joe suggested can recover something, your data is simply gone (and I doubt that will help at this point).

 

When you formatted the drive, you were writing to the current contents of the drive -- so you simply wiped out all current contents.    You can actually do this even if the drive is physically missing !!  [That's the whole idea of "fault-tolerance" -- you can still read/write to a drive even if it's failed ... and UnRAID will rebuild the actual physical drive when you plug in a new one.]

 

You need to (a) try the reiserfsck Joe suggested;  and (b) if it doesn't help (I suspect that will be the case), let the rebuild finish and then restore your data from your backups.