On occasion I have had to move rman backup pieces around due to disk space shortages, etc. In order to avoid complexities if a restore is required you should re-"register" these backup pieces with rman so that it knows where they are. The CATALOG BACKUPPIECE command serves this purpose.


CATALOG BACKUPPIECE '/path_to_backup_piece/filename1',  '/path_to_backup_piece/filename2', ...

After you are done you should follow up with a crosscheck backup command.