Abstract: A data writing apparatus includes a tape drive, a buffer and non-volatile memory. When a synchronization request is received from a device sending data to be written to a tape, the apparatus is operable to copy data corresponding to the synchronization request from the buffer to the non-volatile memory. The data may be stored in the non-volatile memory until at least the time when the data which it is a copy of is written to the tape from the buffer.

Abstract: A data encryption system with encryption integrity verification includes an encryption engine configured to receive an unencrypted data packet and generate an encrypted data packet based at least in part on the unencrypted data packet. The system also includes a decryption engine in electronic communication with the encryption engine, the decryption engine configured to receive the encrypted data packet and generate a decrypted data packet based at least in part on the encrypted data packet. The system further includes a comparator in electronic communication with the encryption engine and the decryption engine, the comparator configured to receive the unencrypted and decrypted data packets, determine whether the unencrypted and decrypted data packets are identical, and present the encrypted data packet as an output when the unencrypted and decrypted data packets are identical.

Abstract: A data writing apparatus includes a tape drive, a buffer and non-volatile memory. When a synchronization request is received from a device sending data to be written to a tape, the apparatus is operable to copy data corresponding to the synchronization request from the buffer to the non-volatile memory. The data may be stored in the non-volatile memory until at least the time when the data which it is a copy of is written to the tape from the buffer.

Abstract: A system, method and data storage device for encrypting data to provide at-rest data encryption of data in the data storage device. The system includes a compression engine for receiving a host data stream packet and selectively generating a compressed data packet, and an encryption engine in electronic communication with the compression engine for receiving an unencrypted data packet from the compression engine. The unencrypted data packet comprises the compressed data packet when the compression engine generates the compressed data packet. The unencrypted data packet comprises the host data packet when the compression engine does not generate the compressed data packet. The encryption engine generates an encrypted data packet having an encrypted component corresponding to the unencrypted data packet and a set of meta data indicative of one or more characteristic of the encrypted data packet.

Abstract: In one embodiment, a method and apparatus for minimizing unload times in a tape drive system is disclosed. The method includes: writing to a tape in serpentine format; reaching a comparison point on the tape, wherein at the comparison point an actual capacity is compared to an expected capacity; utilizing the comparison at the comparison point to estimate a distance from the comparison point until a guaranteed capacity for the tape is reached; and determining a turn-around point on the tape based on the estimated distance, wherein at the turn-around point a tape drive writing to the tape to stop writing in a first direction and then continue writing in a second direction opposite from the first direction and towards a physical beginning of the tape. Other embodiments are also disclosed.

Abstract: In one embodiment, a method and apparatus for minimizing unload times in a tape drive system is disclosed. The method includes: writing to a tape in serpentine format; reaching a comparison point on the tape, wherein at the comparison point an actual capacity is compared to an expected capacity; utilizing the comparison at the comparison point to estimate a distance from the comparison point until a guaranteed capacity for the tape is reached; and determining a turn-around point on the tape based on the estimated distance, wherein at the turn-around point a tape drive writing to the tape to stop writing in a first direction and then continue writing in a second direction opposite from the first direction and towards a physical beginning of the tape. Other embodiments are also disclosed.

Abstract: The system for gap positioning optimization in a tape drive takes advantage of the presence of a pair of read heads, located one on either side of the write head, to precisely determine the boundary between the inter-block gap and the data blocks adjoining the inter-block gap. In particular, the servo mechanisms in the tape drive note the location of the boundary between the present data block and the inter-block gap formed a the end of the present data block. When the tape is repositioned between data read/write operations, this servo information is used to identify this boundary to initiate the subsequently received data read/write operation. A predetermined amount of inter-block gap is provided at the end of the data block to ensure that subsequently received data is not written on top of the present data block or the overwriting of the next data record begins at the beginning of the data block.

Abstract: Method and apparatus for temporarily storing multiple data records in a data processing system which includes a host computer, a cache buffer subsystem, and a magnetic tape drive subsystem. A microprocessor, acting in part as a cache manager, directs the transfer of data into and out of a memory in the cache buffer subsystem by setting up a fill address register, a drain address register, and a start of record address register. Through utilization of a CRC byte to detect errors without correction, and a stop bit to locate the end of a record, values of the registers are compared dependent upon whether there is data being filled or drained to properly manage the temporary storage of data within the memory.