Abstract: A method of de-duplicating duplicate data in a data storage system that includes identifying a plurality of portions of data, comparing each portion of the data to identify duplicate data and identifying a link associated with each duplicate data, determining whether a Hamming link-separation-distance between the identified link and all other existing links is greater than twice the Hamming radius of an error correction code in the data storage system, and then replacing the duplicate data with the identified link.

Abstract: A method is disclosed to store information in multiple holographic data storage media. The method supplies a first holographic data storage medium, defines an inner storage portion of that first holographic data storage medium, and defines an outer storage portion of that first holographic data storage medium. The method further supplies a second holographic data storage medium, defines an inner storage portion of that second holographic data storage medium and defines an outer storage portion of that second holographic data storage medium. The method provides information, encodes a hologram comprising that information into the outer storage portion of the first holographic data storage medium, and encodes the information in the inner storage portion of the second holographic data storage medium.

Abstract: Data hologram recycling systems, methods and computer program products are configured to arrange data for storage in the intermediate data storage as data segments which are replicas of holographic storage segments for destaging to the holographic data storage, and to determine retrieval for recycling of the destaged holographic storage segments to which aggregated requests for deletion are directed. The retrieval determination may be based on a plurality of policies.

Abstract: A method is disclosed to store information in a holographic data storage medium. The method supplies a holographic data storage medium and provides information. The method defines an Active storage portion for the holographic data storage medium and establishes a threshold access interval. The method determines if the information was last accessed within the threshold access interval. If the information was last accessed within said threshold access interval, the method then stores that information as one or more holograms encoded in said Active storage portion of the holographic data storage medium.

Abstract: To improve reliability for multi-layer media, a data stream U is received for recording to a multi-layer rotating storage medium, the data stream U comprising a sequence of data bits. Each data bit U(J) is encoded into X representation bits. A first representation bit B(1,J) is recorded onto a first layer of the storage media, the second representation bit B(2,J) is recorded onto a second layer of the storage media, etc. When a request to read the recorded data U from the storage media is subsequently received, a plurality of the X representation bits are read back from the storage media and are decoded into the original data bit U(J). One embodiment employs a convolution encoding algorithm and PRML decoding algorithm. Another embodiment employs Reed Solomon encoding/decoding.

Abstract: Handling a magnetic tape cartridge comprises the steps of reading cartridge mount information from the cartridge memory; determining from the cartridge mount information whether the present mount is the first mount of the magnetic tape cartridge; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge, e.g., the fast forward is to end of tape (EOT) and the rewind is to beginning of tape (BOT). Alternatively, if the cartridge mount information indicates the present mount is the first mount of the magnetic tape cartridge; monitoring input/output with respect to the magnetic tape cartridge for write errors during the mount; determining whether the number of monitored write errors meets a predetermined threshold; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge.

Abstract: Holographic recording drives encode data for recording into a holographic medium. The steps comprise run length limited encoding three bytes of data into 5×5 matrix information, the data subject to a 4-byte error correction code; and providing the 5×5 matrix information to a spatial light modulator (SLM), as a portion of a two-dimensional pixel matrix of the spatial light modulator, for recording into a holographic image on the holographic medium.

Abstract: A medium, system, and method are disclosed for a common data storage medium depression depth. An optical data storage medium comprises a plurality of spacer layers and data surfaces. A wavelength for a radiation beam such as the emission of a laser diode is identified. The index of refraction for a first spacer layer or substrate is also identified. The substrate is configured to transmit the radiation beam. The index of refraction of a second spacer layer that is configured to transmit the radiation beam is also identified. A depression depth for a plurality of pits for ROM media, or sector headers for recordable media, or grooves for recordable media on each data surface is substantially equal to the radiation beam wavelength divided by four times the average of the indexes of refraction of each spacer layer. In one embodiment, the average is an arithmetic mean of the indexes of refraction. In an alternate embodiment, the average is a harmonic mean of the indexes of refraction.

Abstract: An apparatus, system, and method are disclosed for implementing protected partitions in storage media. The apparatus includes a control module configured to communicate with a host and receive read/write commands for a storage device, and a protection module operating within the control module and configured to maintain a plurality of protection states for the partition and a plurality of allowable transitions between the protection states. The system includes the apparatus, a host device, and a storage device coupled with the host, the storage device including an enclosure having storage media and a control module. The method includes communicating with a host device and receiving read and write commands for a storage device having at least one partition, and maintaining a plurality of protection states for the partition and a plurality of allowable transitions between the protection states on a control module located within the storage device.

Abstract: Data for storage by holographic data storage is arranged in an intermediate data storage as data segments which are replicas of holographic storage segments. Files of data are aggregated into the data segments, and a destaging control determines the destaging of the data segments to the holographic data storage in accordance with a plurality of policies, such as whether a segment is full, a time threshold has been reached, or whether a threshold number of segments are “open”. The intermediate data storage may be arranged into a number of partitions at least equal to the number of sources having input to the data destaging system, the partitions comprising integral multiples of the data segments.

Abstract: An apparatus, system, and method are disclosed for setting protection states of protected partitions in storage media. The apparatus includes a control module configured to receive protection state transition commands from a host for a target partition, a check module configured to verify a protection state for the target partition, and a write module configured to perform the protection state transition according to a plurality of defined allowable state transitions. The system includes a host device, a storage device coupled with the host, the storage device comprising an enclosure having storage media and a control module, and the apparatus. The method includes receiving protection state transition commands from a host for a target partition, verifying a protection state for the target partition, and performing the protection state transition according to a plurality of defined allowable state transitions.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. A control system, for example of a data storage drive, is configured to allocate at least portions of capacity of the data storage media to cartridge memories of the data storage cartridge; and to provide information defining the allocated portions of capacity to the cartridge memories. Each of the cartridge memories may have a separate user and thus provide access for that user to separate partitions.

Abstract: Provided are a method, storage controller, and tape drive for adjusting read heads based on misregistration calculated from servo patterns. A plurality of first read heads read a plurality of servo patterns on a storage medium. A determination is made from the read servo patterns a skew at which the first read heads are positioned with respect to the servo patterns written to the storage medium. A determination is made of an adjustment factor to eliminate the determined skew. A plurality of second read heads that read the storage medium are adjusted by the adjustment factor.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. A control system, for example of a data storage drive, is configured to allocate at least portions of capacity of the data storage media to cartridge memories of the data storage cartridge; and to provide information defining the allocated portions of capacity to the cartridge memories. Each of the cartridge memories may have a separate user and thus provide access for that user to separate partitions.

Abstract: An apparatus for controlling an electric motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the electric motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the electric motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. A control system, for example of a data storage drive, is configured to allocate at least portions of capacity of the data storage media to cartridge memories of the data storage cartridge; and to provide information defining the allocated portions of capacity to the cartridge memories. Each of the cartridge memories may have a separate user and thus provide access for that user to separate partitions.

Abstract: In a system including an application subsystem node having an application RSID table and a logging subsystem node having a logging RSID table, the application subsystem node makes a determination of a registration status of a ALSI string relative to the application RSID table during a logging operation of the ALSI string. The application subsystem node further transfers a RSID package from the application subsystem node across a network to the logging subsystem node, wherein the RSID package includes a RSID encoding of the ALSI string and conditionally includes the ALSI string based on the registration status of the ALIS string relative to the application RSID table as determined by the application subsystem node.

Abstract: Data for storage by holographic data storage is arranged in an intermediate data storage as data segments which are replicas of holographic storage segments. Files of data are aggregated into the data segments, and a destaging control determines the destaging of the data segments to the holographic data storage in accordance with a plurality of policies, such as whether a segment is full, a time threshold has been reached, or whether a threshold number of segments are “open”. The intermediate data storage may be arranged into a number of partitions at least equal to the number of sources having input to the data destaging system, the partitions comprising integral multiples of the data segments.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. A control system, for example of a data storage drive, is configured to allocate at least portions of capacity of the data storage media to cartridge memories of the data storage cartridge; and to provide information defining the allocated portions of capacity to the cartridge memories. Each of the cartridge memories may have a separate user and thus provide access for that user to separate partitions.

Abstract: Holographic recording drives encode data for recording into a holographic medium. The steps comprise run length limited encoding three bytes of data into 5×5 matrix information, the data subject to a 4-byte error correction code; and providing the 5×5 matrix information to a spatial light modulator (SLM), as a portion of a two-dimensional pixel matrix of the spatial light modulator, for recording into a holographic image on the holographic medium.