Abstract: According to an embodiment, a magnetic disk has a plurality of second servo sectors and a plurality of third servo sectors each arranged between two second servo sectors of the plurality of second servo sectors, in which the second and third servo sectors are arranged in a circumferential direction. A controller performs a first demodulation for detecting a servo mark and demodulating a burst pattern on the servo data in each second servo sector. The controller performs a second demodulation for demodulating the burst pattern without detecting the servo mark, on the servo data in each third servo sector. The controller performs the second demodulation on the servo data in a fourth servo sector which is one of the plurality of second servo sectors in a case where the detection of the servo mark fails when the first demodulation is performed on the servo data in the fourth servo sector.

Abstract: An electronic system includes a file system configured to assign logical block addresses corresponding to consecutive pieces of data sets of segments in a plurality of zones. The electronic system also includes a memory device including a plurality of memory blocks, and a memory controller configured to map the logical block addresses to physical block addresses corresponding to consecutive pages in the plurality of memory blocks to program the consecutive pieces of data to the consecutive pages in the plurality of memory blocks. The file system is configured to assign new logical block addresses corresponding to consecutive pieces of a data file to invalid segments in the plurality of zones.

Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data with respect to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a radial direction of the disk, performs first alternative processing of recording a first user sector in a first region when writing of the first user sector available by a user in the first track is disabled, and performs second alternative processing different from the first alternative processing of recording a first parity sector in a second region when writing of the first parity sector acquired by an XOR operation in the first track is disabled.

Abstract: A data storage device is disclosed comprising a non-volatile storage medium (NVSM) having a plurality of data sectors and a plurality of reserve sectors. A map-out value is generated for each of a first plurality of the data sectors based on a read latency of each of the first plurality of data sectors, and when the map-out value of a first data sector in the first plurality of data sectors exceeds a threshold, a first logical block address (LBA) is mapped from the first data sector to a first reserve sector. When the map-out value of a second data sector in the first plurality of data sectors exceeds the map-out value of the first data sector, the first LBA is mapped from the first reserve sector back to the first data sector, and a second LBA is mapped from the second data sector to the first reserve sector.

Abstract: Magnetic recording media including a soft magnetic underlayer (SUL) formed over a plasma-polished substrate or pre-seed layer. In some examples, the substrate or pre-seed layer is plasma-polished using an inert gas such as krypton so that the roughness of the surface on which the SUL is deposited is reduced. The roughness reduction can lead to improved crystallographic texture within subsequently deposited media films, and consequently, to increased recording performance of the media. In particular, media signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a carbon deposition/etching apparatus may be modified to polish the substrate or pre-seed layer with krypton or other inert gases, rather than be used to deposit carbon overcoat.

Abstract: According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

Abstract: According to one embodiment, a magnetic disk device includes a controller that disposes a plurality of conventional magnetic recording division regions and a plurality of shingled write magnetic recording division regions in the user data region, sets, when receiving a command to write data to a first LBA, a first conventional magnetic recording region to a first conventional magnetic recording division region, and sets, when receiving a command to write data to a second LBA, a first shingled write magnetic recording region to a first shingled write magnetic recording division region.

Abstract: A host/device interface coupled between a host and a storage device, and including a data interface and a Quality of Service (QoS) and configured to communicate a QoS signal with the host. The QoS interface cooperates with the data interface to selectively manage a storage QoS on the storage device. A method is provided for storing data on a data medium including receiving a Quality of Service (QoS) command; selecting a portion of the data medium on which to store a data stream; forming a stream chunk from a portion of the data stream; configuring a transducer to store the stream chunk on the data medium in response to the QoS command; and storing the data on the data medium, such that the storing conforms to a QoS command value.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, and a controller that sets at least a set of a first target position and a second target position to be matched, among a plurality of the first target positions respectively corresponding to a plurality of first tracks in a case where writing on the first tracks is performed to the first region of the disk in a radial direction of the disk under a first recording mode, and a plurality of the second target positions respectively corresponding to a plurality of second tracks in a case where writing on the second tracks is performed to the first region in the radial direction under a second recording mode different from the first recording mode.

Abstract: A data storage device is disclosed comprising at least one head configured to access a magnetic tape comprising a plurality of servo frames each comprising a plurality of servo bursts, wherein each servo burst comprises a plurality of servo stripes. The servo stripes in a first servo burst are read using the head to generate a first read signal that is processed using a first matched filter matched to the first servo burst in order to generate an average time stamp for the servo stripes in the first servo burst. A position error signal (PES) is generated based on the average time stamp of the first servo burst, and the head is positioned relative to the magnetic tape based on the PES.

Abstract: A storage system having a processor that provides a volume to be an object of an input/output (I/O) request and executes I/O in response to the I/O request includes a valid volume provided to be the object of the I/O request, and an invalid volume not being provided to be the object. A plurality of invalid volumes includes invalid volumes of a plurality of types of capacities. The processor selects, when a volume creation request is received, the invalid volume on the basis of capacity according to the volume creation request to convert the selected invalid volume into a valid volume, and provides the validated valid volume.

Abstract: According to one embodiment, a magnetic disk device includes a disk having a first sector including first servo data, first user data, and first correction information used to correct a data error, a head that writes data to the disk and that reads data from the disk, and a controller that changes, according to a first defect length of a defect generated in the first sector in a circumferential direction of the disk, a first sector length of the first sector in the circumferential direction.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that executes error correction on a first sector which is unreadable in a first track from an initial reading time of initially one-round reading the first track of the disk based on first parity data corresponding to the first track.

Abstract: Storage pools having categorized archival storage tapes according to content of files stored on each tape. Archiving new files into the storage pools according to content of the new files for efficient retrieval of files from storage tapes organized by category of content. Recall of multiple files from archival storage tapes to primary storage of an hierarchical storage management system is efficiently performed such that tape mounting operations are minimized.

Abstract: A magnetic recording medium includes a substrate, an underlayer disposed above the substrate, and a first magnetic layer disposed above the underlayer. The first magnetic layer has a granular structure including magnetic grains having a L10 structure, and grain boundaries. A content of the grain boundaries is in a range of 25 volume percent to 50 volume percent, and the grain boundaries include a chalcogenide-based layered material.

Abstract: A multi-actuator storage device includes separate actuators that can be used to access a storage medium. A property of a request can be analyzed to determine which actuator to use to access data associated with the request. For example, high-priority requests can be handled by an actuator designated for random I/O requests, whereas low-priority requests can be handled by an actuator designated for sequential I/O requests. Writes can be treated as low-priority requests. In a particular embodiment, a priority bit can be used to determine which actuator is used to access the data.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a storage unit, a magnetic head, an error correction unit that, in a case where an error is detected in user data read by the magnetic head, performs error correction on a sector in which the error is detected in track units and acquires error correction data, and a control unit. The control unit controls reading/writing of user data, management data for managing a sector on which the error correction is performed in the track units, and the error correction data, and in a case where there is no host access, rewrites data on the track including the sector on which the error correction is performed, based on the user data stored in the track and the error correction data of the sector, in which the error is detected, of the track.

Abstract: A packet forwarding method and apparatus pertaining to the field of communications technologies are disclosed. The method includes: determining whether a current to-be-sent target packet is a header packet or a following packet in a burst sequence; when the target packet is the following packet in the burst sequence, obtaining port information of an egress port used to send the burst sequence, where the port information of the egress port is determined and stored when the header packet in the burst sequence is sent, and the burst sequence is a sequence including a plurality of packets that belong to a same service flow; and sending the target packet through the obtained egress port.

Abstract: In examples, a list of elements may be divided into spans and each span may be allocated a respective memory range for output based on a worst-case compression ratio of a compression algorithm that will be used to compress the span. Worker threads may output compressed versions of the spans to the memory ranges. To ensure placement constraints of a data structure will be satisfied, boundaries of the spans may be adjusted prior to compression. The size allocated to a span (e.g., each span) may be increased (or decreasing) to avoid padding blocks while allowing for the span's compressed data to use a block allocated to an adjacent span. Further aspects of the disclosure provide for compaction of the portions of compressed data in memory in order to free up space which may have been allocated to account for the memory gaps which may result from variable compression ratios.

Abstract: In accordance with one implementation, a method for mitigating cache transfer time entails reading data into memory from at least two consecutive elliptical data tracks in a main store region of data storage and writing the data read from the at least two consecutive elliptical data tracks to a spiral data track within a cache storage region.

Abstract: A processing device of a system receives a request to access a selected sector in a memory component. The selected sector is associated with a sector number. The processing device determines a virtual block corresponding to the selected sector. The virtual block is associated with a misalignment factor and a misalignment counter. The processing device determines if the misalignment counter satisfies a threshold criterion. In response to the misalignment counter satisfying the threshold criterion, the processing device generates an updated sector number by shifting the sector number by the misalignment factor and performs the access to the selected sector using the updated sector number. In response to the misalignment counter not satisfying the threshold criterion, the processing device updates the misalignment counter and performs the access to the selected sector using the sector number.

Abstract: A magnetic tape drive for writing data to a magnetic tape that includes a first data band, a second data band, and a servo band that is positioned between the first data band and the second data band, each of the data bands including a plurality of wraps including a first wrap and a last wrap, includes a drive controller and a tape head. The drive controller defines at least a first partition and a second partition within the magnetic tape. The tape head is configured to write data to the first partition of the magnetic tape and subsequently write data to the second partition of the magnetic tape. The drive controller defines an end of the first partition to be directly after the last wrap of the first data band. The drive controller controls the tape head to write data to all of the plurality of wraps of the first data band.

Abstract: A storage device and a method of operating a storage device including a non-volatile memory. The method includes selecting a first task from among a plurality of tasks queued in a task queue of the storage device; determining whether a mode of the first task is identical to a mode of a previously-executed task; and determining an execution order of the first task according to a result of determination. The modes and the region addresses of tasks may be utilized to group tasks to permit interleaving of programming data.

Abstract: A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator, where the victim feedforward signal is configured to compensate for disturbances to a victim head caused by assertion of the aggressor VCM control signal. Each aggressor VCM control signal is asserted at a specific time by the aggressor actuator, for example in response to the aggressor head passing over a first servo wedge. A feedforward signal that compensates for the effect of the aggressor VCM control signal is then determined based on the aggressor VCM control signal, stored, and asserted via the victim microactuator at a predetermined time relative to when the aggressor VCM control signal is asserted.

Abstract: A computer-implemented method can include obtaining tape data for one or more tapes. The tape data can include pointer data corresponding to a first file. The method can further include determining, based on the tape data, that the first file is stored on a first tape of the one or more tapes. The first tape can have an export status. The method can further include determining that the pointer data includes a pointer to the first tape and a pointer to a second tape. The second tape can have a non-export status. The method can further include storing at least a portion of the tape data. The method can further include initiating, based on the first tape having the export status, a deactivation of the pointer to the first tape.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, and a controller. The magnetic disk has a plurality of tracks. The magnetic head performs reading and writing from and to the magnetic disk. The controller controls write operations to a first region and a second region of the magnetic disk in different manners. The second region is narrower in track pitch than the first region.

Abstract: A data storage device is disclosed comprising at least one head configured to access a magnetic tape comprising a plurality of data tracks, wherein each data track comprises a plurality of data segments and a plurality of servo sectors. The head is used to read one of the servo sectors to generate a first read signal. The first read signal is processed to generate a position error signal (PES) of the head relative to the magnetic tape, wherein the head is positioned relative to the magnetic tape based on the PES. The head is used to read one of the data segments to generate a second read signal, wherein the second read signal is processed to detect user data recorded in the data segment.

Abstract: An apparatus in one embodiment comprises a host device that is configured to communicate over a network with at least one storage system comprising a source logical storage volume and a target logical storage volume. Responsive to a reboot of the host device during a migration of a plurality of chunks of data from the source logical storage volume to the target logical storage volume, the host device is configured to determine, based at least in part on an entry of a copy migration journal, the entry corresponding to a given chunk of the plurality of chunks, that the migration of the given chunk was in progress prior to the reboot. Responsive to determining that the migration of the given chunk was in progress prior to the reboot, the host device is configured to resume the migration of the plurality of chunks from the given chunk.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a servo sector including burst data, a head including a write head which writes data to the disk, and a read head which reads data from the disk, and a controller which generates a first normal servo gate for applying servo read to the servo sector, wherein when a short servo gate for at least applying servo read to the burst data is generated, the controller generates the short servo gate and the first normal servo gate, and when the short servo gate is not generated, the controller generates the first normal servo gate and a second normal servo gate different from the first normal servo gate.

Abstract: A memory system includes a first nonvolatile memory, a first bridge circuit connected to the memory, a second nonvolatile memory, a second bridge circuit connected to the second memory and connected to the first circuit, and a controller connected to the first circuit and configured to output, to the first circuit, first data to be stored in the first memory and second data to be stored in the second memory, the first and second data being mapped to multiplexing symbols. The first bridge circuit is configured to, upon receipt of the multiplexing symbols, extract the first data from the symbols, store the first data in the first memory, generate third data based on the second data to insert the generated third data into the multiplexing symbols where the first data was mapped, and output to the second circuit the multiplexing symbols into which the third data has been inserted.

Abstract: A servo pattern recording method according to an embodiment of the present technology is a servo pattern recording method of recording a servo pattern on a tape-like magnetic recording medium including a magnetic layer including five or more servo bands, the method including: determining at least three first servo bands in which first servo band identification information constituted by a plurality of bits is to be recorded, and at least two second servo bands in which second servo band identification information constituted by a plurality of bits is to be recorded, the second servo band identification being different from the first servo band identification information; and recording each of the first servo band identification information and the second servo band identification information in the first servo band and the second servo band on the same phase.

Abstract: Storage device self-servo-write includes generating a time base frequency signal, generating a sampled frequency signal by sampling the time base frequency signal at a sample rate to obtain a first set of samples, decimating those samples at a decimation rate to obtain a second set of samples at a spiral frequency of which the time base frequency is a first integer multiple, detecting a spiral track based on the spiral frequency, and writing a servo pattern based on the spiral track and the time base frequency. A generated sampled frequency obtained by sampling the time base frequency signal at the sample rate is used as the servo write frequency, of which the time base frequency is a second integer multiple. Alternatively, the time base frequency is multiplied by a first rational multiple so that the time base frequency is a second rational multiple of the servo write frequency.

Abstract: An access operation performed by a tape drive is detected. The access operation is performed on a tape medium. The access operation has one or more performance characteristics. The performance characteristics of the detected access operation are compared with one or more predefined performance thresholds. The comparison is in response to detecting the access operation. An operation performance of the tape medium is determined. The determination is based on comparing the performance characteristics with the predefined performance thresholds. A table associated with the tape medium is updated based on the operational performance of the tape medium. The table is stored in a non-volatile storage.

Abstract: A method for data storage tape access optimization is provided. The method identifies a plurality of data segments stored on a data storage tape. Each segment having a location and a size on the data storage tape. The method determines a subset of data segments stored on the data storage tape selected for retrieval. The method determines an access order for the subset of data segments. The access order represents a minimized tape cycle time for retrieving the subset of data segments. The method retrieves the subset of data segments from the data storage tape based on the access order.

Abstract: Apparatuses, systems, methods, and computer program products are disclosed for key-value stores with partial data access. An interface module is configured to receive a data object for storage in a key-value store. The data object may include a key and a value. A block object module is configured to generate a plurality of block objects smaller than the data object. A block object may include a new key and a new value. The new key may be based on the key for the data object and on metadata for the new value. The new value may be based on at least a portion of the value for the data object. A storage module is configured to store the block objects in the key-value store.

Abstract: In one embodiment, a guide layout creating apparatus includes a selection module that selects a first point as a point on which a guide to array a plurality of particles in a first array is arranged. The apparatus further includes a calculation module that calculates first free energy when the plurality of particles are arrayed in the first array by the guide arranged on the first point, and second free energy when the plurality of particles are arrayed in a second array by the guide arranged on the first point, a type of the second array being different from a type of the first array. The apparatus further includes a determination module that determines whether the first point is employed as the point on which the guide is arranged on the basis of the first free energy and the second free energy.

Abstract: According to one embodiment, a magnetic disk device includes a disk having a first region to which data is written by normal recording and a second region to which data is written by shingled recording, a head configured to write the data to the disk and read the data from the disk, and a controller configured to, when first data and second data is to be sequentially written to a third region of the second region, reserve a fourth region corresponding to the first data and the second data in the first region, write the first data to the fourth region, write the second data after the first data in the fourth region, and sequentially write the first data and the second data read from the fourth region to the third region.

Abstract: A magnetic tape reading apparatus comprises an acquisition unit that acquires information on linearity of a servo pattern to be recorded on a servo band of a magnetic tape, a reading element unit in which at least two reading elements each of which reads data from a specific track region included in the magnetic tape are disposed, a servo reading element that reads the servo pattern, a control unit that performs control of positioning the reading element unit, a derivation unit that derives a deviation amount, and an extraction unit that extracts data recorded on the reading target track by performing a waveform equalization process on each reading result for the reading elements in accordance with the deviation amount.

Abstract: A data storage device is disclosed comprising a head actuated over a non-volatile storage medium. A plurality of access commands are received from a host and sored in a host queue and a pending queue. A first access command is selected from the host queue, wherein the first access command having a first execution time needed to execute the first access command. When a second access command in the pending queue can be executed within the first execution time, the second access command is executed, and after executing the second access command, the first access command in the host queue is executed. After selecting the first access command from the host queue, a third access command is transferred from the pending queue to the host queue based on a first-in-first-out (FIFO) order of the pending queue.

Abstract: A magnetic tape and servo elements of a magnetic head for reading and writing to the magnetic tape can ascertain servo band signals from different servo bands that are vertically aligned and adjacent to one another. When operating in a write or read mode, at least two servo elements can be activated to respond to a write/read operation based on a determined position across a width of the servo bands in the magnetic tape. The determined position is based on various pattern combinations from different servo band identifiers from the servo band signals.

Abstract: Disclosed are a communication method and communication apparatus using an ambient backscatter communication. A transmission apparatus may include generating a plurality of bitsets by fragmenting data based on a predetermined bitset length, mapping the plurality of bitsets to a plurality of switching patterns based on a data size, and controlling a reflection of a background radio frequency (RF) signal based on a corresponding mapped switching pattern, a total number of the plurality of switching patterns may be determined based on the bitset length, and each of the plurality of switching patterns may have a different length.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a first servo sector including a first preamble, a first servo mark, a first gray code, and first burst data, a head including a write head which writes data to the disk and a read head which reads data from the disk, and a controller which stops write processing, based on a write mask gate different from a first servo gate executing read processing of the first servo sector and a write gate executing the write processing to the disk.

Abstract: A data transmission method according to one aspect of the present disclosure includes: generating a plurality of MPUs, reference clock time information, and leading clock time information indicating a leading PTS that is a clock time at which a leading access unit in the MPU is presented, transmitting the generated plurality of MPUs, reference clock time information, and leading clock time information, wherein the leading clock time information indicates the leading PTS of the plurality of MPUs of which presentation is started after the leading clock time information is transmitted in the generated plurality of MPUs, and each of the generated plurality of MPUs indicates a time point at which each access unit that does not exist in a head of the MPU is presented as a relative value to a time point of another access unit in the MPU.

Abstract: Data set groups are determined, wherein each data set group includes a plurality of data sets and each data set includes error-correcting information for content user data of the data set. One or more versions of data set group level error-correcting information for each data set group are calculated. The data set groups on stored a tape storage media. After the data set groups are stored, an amount of storage available on one or more regions of the tape storage media associated with one or more tape edges is identified. An instruction is provided to store at least a partial amount of the calculated one or more versions of data set group level error-correcting information for the data set groups able to be stored in the amount of storage available on the one or more regions of the tape storage media associated with the one or more tape edges.

Abstract: A system and method are disclosed for detecting and handling volume creation failures. In one implementation, a request to create a new volume in a volume chain for a virtual machine is received. A processing device creates a first metadata file for the new volume, where the first metadata file has a first filename indicating that creation of the new volume has not completed. A reference to a parent volume of the new volume is stored in the first metadata file, along with an indication that the new volume is a leaf of the volume chain. A second metadata file that is associated with the parent volume is updated in view of the new volume. The processing device creates a data file for the new volume and renames the first metadata file to a second filename indicating that creation of the new volume has completed.

Abstract: A computer-implemented method for incrementing a tape write pass (WP) value includes identifying an action that requires incrementing a tape WP value on a magnetic tape storage device. The computer-implemented method further includes, in response to identifying the action that requires incrementing the tape WP value on the magnetic tape storage device: assigning a new tape WP value to a dataset based, at least in part, on a partition number corresponding to the data partition in which the dataset is written to.

Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and a difference between a spacing S0.5 measured, after n-hexane cleaning, on a surface of the magnetic layer under a pressure of 0.5 atm by optical interferometry and a spacing S13.5 measured, after n-hexane cleaning, under a pressure of 13.5 atm is 3.0 nm or less, and S0.5 is 5.0 nm or more.

Abstract: According to one embodiment, there is provided a magnetic disk drive comprising a magnetic disk, a magnetic head configured to read/write data from/to the magnetic disk, a signal processing circuit configured to convert data to be recorded on the magnetic disk into a write signal, and to output the write signal to the magnetic head that generates a recording magnetic field corresponding to the write signal, and a recording control circuit configured to control the signal processing circuit and the magnetic head to record, in a target recording area of the magnetic disk, first data in the target recording area with a recording magnetic field having a first frequency, and to write, second data different from the first data over the first data with a recording magnetic field having a second frequency higher than the first frequency.

Abstract: A storage device includes a disk, a head configured to write data to and read data from the disk, and a controller. The controller is configured to, for each of a plurality of unexecuted commands, carry out a calculation of an amount of time that is required for the head to start accessing the disk to begin execution of the non-executed command upon completion of a currently-executed command, until the earlier of i) a number of unexecuted commands for which the calculation has been carried out reaches a threshold value or ii) the completion of the currently-executed command, select a next command to be executed from one or more unexecuted commands for which the calculation has been carried out, based on the calculated amount of time for each of the one or more unexecuted commands, and execute the selected next command.

Abstract: Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).