We received an 8 disk Drobo failure from one of our good clients.
On inspection, 3 of the 8 drives had failed. We repaired the drives that we could and rebuilt the Drobo from what we could of the BeyondRAID system.
After the failure of the last drive (Drobo can still be accessible after 2 drive failures) it appears that the BeyondRAID data was damaged.
We were able to repair the file structure somewhat and recover around 9Tb of data within clusters of the original files. There was quite a bit of corruption as it seemed that the RAID had overwritten vital data, but we were able to recover around 60-70% of good files.