Abstract: A system includes, according to one embodiment, a magnetic head having a plurality of write transducers configured to store data to tracks of a sequential access medium and a plurality of read transducers. Each read transducer is configured to read data from the sequential access medium after being written thereto by a corresponding write transducer. A first of the read transducers is aligned with a first of the write transducers, wherein the output of the first read transducer is produced during read-while-write. The system also includes a controller and logic integrated with and/or executable by the controller. The logic is configured to read, using the plurality of read transducers, encoded data from a plurality of tracks of the sequential access medium simultaneously.

Abstract: Embodiments of the present invention provide a tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. The tape transport control system comprises of circuitry adapted to output and circuitry adapted to receive one or more signals representing a tape velocity, at least one radius of either the first tape reel or the second tape reel, and a tape tension, and based on the received signals, generate at least one control signal to control at least one of the first reel motor or the second reel motor so as to reduce a tension disturbance at a minimum, one frequency corresponding to a time-varying reel-rotation frequency, based on controller parameters that depend on the tape velocity and on the at least one radius of either the first tape reel or the second tape reel.

Abstract: In one embodiment, a system includes a magnetic head having a plurality of write transducers and a plurality of read transducers. Each read transducer is configured to read data from a sequential access medium after being written thereto by a corresponding write transducer. The system also includes a controller and logic integrated with and/or executable by the controller. The logic is configured to read, using the plurality of read transducers, encoded data from a plurality of tracks of the sequential access medium simultaneously. The logic is also configured to determine that one or more tracks of the sequential access medium are dead within a sliding window. Moreover, the logic is configured to rewrite a set of encoded data from the one or more dead tracks to live tracks in a rewrite area of the sequential access medium. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: A determination is made whether read/write is enabled within the tape drive storage unit. In response to determining that read/write is enabled, a determination is made whether an absolute value of a channel offset exceeds a threshold value. In response to determining that the absolute value of the channel offset exceeds a threshold value, a direction of travel of the tape media is determined. In response to determining that the direction of travel of the tape media is a forward direction, a determination is made whether the channel offset is positive. In response to determining that the channel offset is positive, a first cooling device within the tape drive storage unit is powered on. The first cooling device lowers the temperature of a first guide roller and the tape media coming off a first tape storage reel prior to the media passing by a read/write head.

Abstract: In one embodiment, a system includes a magnetic head having a plurality of write transducers and a plurality of read transducers. Each read transducer is configured to read data from a sequential access medium after being written thereto by a corresponding write transducer. The system also includes a controller and logic integrated with and/or executable by the controller. The logic is configured to read, using the plurality of read transducers, encoded data from a plurality of tracks of the sequential access medium simultaneously. The logic is also configured to determine that one or more tracks of the sequential access medium are dead within a sliding window. Moreover, the logic is configured to rewrite a set of encoded data from the one or more dead tracks to live tracks in a rewrite area of the sequential access medium. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: In one embodiment, a method includes writing a data set to a sequential access medium. The method also includes reading the data set immediately after being written to the sequential access medium in a read-while-write process to identify one or more faulty encoded data blocks, each of the one or more faulty encoded data blocks including at least one faulty codeword having symbols at least 10 bits in size. Moreover, the method includes rewriting a first of the one or more faulty encoded data blocks within a first encoded data block set to a particular logical track in the rewrite area of the sequential access medium selected from a predetermined subset of logical tracks. The predetermined subset of logical tracks includes D1+D2+1 logical tracks. Only one faulty encoded data block from a particular sub data set is rewritten in a single encoded data block set in the rewrite area.

Abstract: An apparatus according to one embodiment includes a plurality of first modules each having a first write transducer. The apparatus further includes a plurality of second modules each having a second write transducer. Planes of deposition of write gaps of the second write transducers are oriented at an angle of greater than 4 degrees relative to planes of deposition of write gaps of the first write transducers. The media bearing surfaces of the modules are primarily planar, and lie along offset parallel planes. An apparatus according to another embodiment includes a first module having a plurality of first write transducers. The apparatus further includes a second module having a plurality of second write transducers. Planes of deposition of write gaps of the second write transducers are oriented at an angle of greater than 4 degrees relative to planes of deposition of write gaps of the first write transducers.

Abstract: A method according to one embodiment includes generating a y-position estimate based on a servo readback signal from a servo reader reading a servo band, retrieving or calculating a nonlinearity-correction value corresponding to the y-position estimate, adjusting the y-position estimate using the nonlinearity-correction value, and outputting the adjusted y-position estimate. A computer program product for compensating for nonlinearity in a timing based servo pattern according to one embodiment includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are readable and/or executable by a controller to cause the controller to perform the foregoing method.

Abstract: A tape drive-implemented method, according to one embodiment, includes: using information read from one or more servo bands on a magnetic tape to position a magnetic tape head relative to the magnetic tape. An array of data transducers is positioned along the magnetic tape head, the array extending perpendicular to a direction of travel of the magnetic tape. Moreover, a group of servo readers is positioned at each end of the array of data transducers. A distance between each of the immediately adjacent servo readers in each of the groups of servo readers is less than or equal to one third of a prespecified width of each of the servo bands. Furthermore, the distance between each of the servo readers in each of the groups and the prespecified width are both measured in a direction perpendicular to the direction of travel of the magnetic tape.

Abstract: An apparatus according to one embodiment includes a plurality of first modules each having a first write transducer, and a plurality of second modules each having a second write transducer. Planes of deposition of write gaps of the second write transducers are oriented at an angle of greater than 4 degrees relative to planes of deposition of write gaps of the first write transducers. An apparatus according to another embodiment includes a first module having a plurality of first write transducers, and a second module having a plurality of second write transducers. Planes of deposition of write gaps of the second write transducers are oriented at an angle of greater than 4 degrees relative to planes of deposition of write gaps of the first write transducers.

Abstract: A tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. For example, a closed-loop control system for controlling a tape transport includes circuitry adapted to output a signal representing a tape velocity at a tape head, circuitry adapted to output a signal representing a tape velocity at the first tape reel and a signal representing a tape velocity at the second tape reel, circuitry adapted to output a signal representing a tape tension, and circuitry adapted to, based on the received signals, generate control signals to control the tape velocity at least at one of the tape head, the first tape reel, the second tape reel, and the tension of the tape, using controller gains that depend on a longitudinal position of the tape, and to implement a system transfer function that is approximately independent of the longitudinal position.

Abstract: An apparatus-implemented method according to one embodiment includes passing a magnetic recording tape over a plurality of modules having write transducers. Associated pairs of the write transducers are aligned along an intended direction of tape travel thereacross, and planes of deposition of write gaps of the write transducers in each associated pair are oriented at an angle of greater than 4 degrees relative to each other. The method further includes controlling a timing of writing of each of the write transducers individually for causing each pair of write transducers to write magnetic bars on the magnetic recording tape that are offset from one another in the intended direction of tape travel thereacross.

Abstract: Predictively selecting a subset of disks of a storage system to be spun-up, including providing metadata of data entities stored in the disks of the storage system, estimating the data entity access probabilities for a prediction time window based on said metadata, each data entity access probability being indicative for the probability of access to a certain data entity within said prediction time window, calculating disk access probabilities for a prediction time window based on the estimated probability of access of data entities, each disk access probability being indicative for the probability of access to a certain disk within said prediction time window, estimating the number of disks to be spun-up in a certain prediction time window, dynamically adapting the data entity threshold value and/or the disk access threshold value, selecting a subset of disks to be spun-up in the following prediction time window.

Abstract: A tape drive-implemented method, according to one embodiment, includes: causing a servo reader to move in a first direction over a high-density servo pattern which includes a plurality of high-density servo tracks. Each of the servo tracks includes at least two patterns written at different frequencies to produce different periodic waveforms during readback. Moreover, a readback signal is received from the servo reader as the servo reader moves in the first direction. The readback signal is used to set a gain parameter for each of the respective periodic waveforms. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A tape drive-implemented method, according to one embodiment, includes: determining a length of a window of a servo pattern to use for calculating a lateral position estimate, and determining a number of the windows of the servo pattern to use for calculating a lateral position value. A lateral position estimate is calculated for each of the number of the windows of the servo pattern using signals which correspond to each of the number of the windows. Moreover, the lateral position value is calculated by using the lateral position estimates. The lateral position value is used to control a tape head actuator. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A tape drive-implemented method, according to one embodiment, includes: determining a length of a window of a servo pattern to use for calculating a lateral position estimate, and determining a number of the windows of the servo pattern to use for calculating a lateral position value. A lateral position estimate is calculated for each of the number of the windows of the servo pattern. Moreover, the lateral position value is calculated by using the lateral position estimates. The lateral position value is used to control a tape head actuator. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: The invention is notably directed to computer-implemented methods and systems for managing datasets in a storage system. In such systems, it is assumed that a (typically small) subset of datasets are labeled with respect to their relevance, so as to be associated with respective relevance values. Essentially, the present methods determine, for each unlabeled dataset of the datasets, a respective probability distribution over a set of relevance values. From this probability distribution, a corresponding relevance value can be obtained. This probability distribution is computed based on distances (or similarities), in terms of metadata values, between said each unlabeled dataset and the labeled datasets. Based on their associated relevance values, datasets can then be efficiently managed in a storage system.

Abstract: An apparatus according to one embodiment includes a first module having a plurality of first write transducers, and a plurality of second modules each having a second write transducer. Planes of deposition of write gaps of the second write transducers are oriented at an angle of greater than 4 degrees relative to planes of deposition of write gaps of the first write transducers.

Abstract: A unidirectional and bi-directional tape head with sub-ambient pressure cavities. The tape head is adapted for reading and/or writing to a magnetic tape. The tape head includes: a tape-bearing surface; a transducer area, having at least one transducer designed for reading and/or writing to the magnetic tape; a cavity open on the tape-bearing surface adjacent to the transducer area that extends parallel to the transducer area and transversally to the longitudinal direction of circulation of the tape such that an opening of the cavity faces the tape in operation; and one or more air bleed slots connected to the cavity. The cavity is further dimensioned and arranged with respect to the transducer area to create, upon circulation of the tape in operation, sub-ambient pressure therein.

Abstract: Embodiments of the present invention provide a tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. The tape transport control system comprises of circuitry adapted to output and circuitry adapted to receive one or more signals representing a tape velocity, at least one radius of either the first tape reel or the second tape reel, and a tape tension, and based on the received signals, generate at least one control signal to control at least one of the first reel motor or the second reel motor so as to reduce a tension disturbance at a minimum, one frequency corresponding to a time-varying reel-rotation frequency, based on controller parameters that depend on the tape velocity and on the at least one radius of either the first tape reel or the second tape reel.