I/O device error
This situation may arise if an external hard drive containing B2D files is moved from one media server to another media server, or if Backup Exec is uninstalled and reinstalled, even on the same machine. Backup Exec will not recognize the B2D files until a successful inventory can be performed on the B2D folders.
To inventory and catalog the B2D files, successfully follow the below steps :-
1. Delete the Changer.cfg and Folder.cfg files from the B2D folder as shown below.
2. Create a new B2D folder within Backup Exec, and point it to the same hard drive location where the B2D files are residing.
Backup Exec should then be able to inventory successfully so that catalog operations can be performed.

Note: If the B2D folder had been created before the files above were removed, delete the newly created B2D folder from Backup Exec, and then create another folder after deleting the .cfg files as instructed above.