RMAN-06481: backup piece 'string' cannot be found on the storage medium
Cause: The CHANGE BACUKPPIECE AVAILABLE command was used, but the backup piece cannot be found on the storage medium.
Action: If the storage containing the backup piece has been removed from the host, then restore it and retry the command. If the backup piece is permanently gone, then issue the CHANGE BACKUPPIECE DELETE command for this backup piece.