A method, computer management apparatus, and computer program product are provided for processing data stored on a sequential storage media within a computational computing environment. A block reference table and most often read blocks are loaded from a modified tape format of a sequential storage media into an internal memory of a sequential storage media device. During write command processing, a data deduplication procedure is performed using a modified block reference table. It is determined if entries from the block reference table must be deleted and responsive to this identifying and deleting host block and device block entries from the block reference table.