BEX 2012

Changer.cfg and folder.cfg are the configuration files for the B2D. These files are always present in a B2D. Id these are deleted, then the B2D needs to be recreated. And recreating the B2D should not be a problem.

servername-.DR file is the .DR file of that particular server whose full backup (SDR enabled) was run. Deleting this file will affect SDR recovery of the server. Running another full backup will recreate this file.

.bkf are the actual backup sets. From the Storage tab, choose the B2D and confirm if all backup sets are deleted or not. If not, try deleting them again and see if the sets are deleted from the physical disk. Else, try to delete the backup sets from the physical disk, inventory the disk from the UI and test the storage for a backup.