Interestingly unexpected results

[Tophicles]

Hi gang!

So, I had two drives go bad and replaced them with two other drives, formatted XFS.

Completed the "Data-Rebuild" process and ... both drives are empty?

I have dual parity drives so I assumed I could lose two data drives.

C'est ce que c'est?

[JorgeB]

2 minutes ago, Tophicles said:

and replaced them with two other drives, formatted XFS

Format is never part of a rebuild, if you formatted those disks at any point before or during the rebuild existing data was deleted.

[Squid]

2 minutes ago, Tophicles said:

replaced them with two other drives, formatted XFS.

By formatted XFS, do you mean that the drives were showing up as "Unmountable" and you clicked the check-box and then said Format?  If so, you formatted the emulated drives and lost the info. 

[Tophicles]

Yes, I assumed that was what I needed to do to change the FS to XFS and the data-rebuild would then re-construct the contents.

My bad then, I guess I misunderstood the process.

[JorgeB]

You can't use a rebuild to convert filesystem, it can only rebuild the previously used filesystem, if you need more info see here:

 

[trurl]

Format means "write an empty filesystem to this disk" (always has on every OS). unRAID parity is realtime. unRAID treats this write operation just like it does every other write, by immediately updating parity. So rebuilding a formatted disk from parity results in a formatted disk.