Abstract: According to one embodiment, a measurement method is applied to a disk device including a disk, and a head configured to protrude toward the disk when power is supplied thereto. In the method, a reference value for each of areas of the disk is acquired from a measurement-value distribution including pre-measured values that correspond to power supplied to a heater when the head is brought into contact with the disk. In each area, a data group calculated from the distribution and the reference value is acquired. An area where the data group has lower values than in the other areas is selected as a first area to be firstly measured. An area to be measured subsequent to the first area based on the data group is selected.

Abstract: Various embodiments of a method and system for preserving data of a data storage device are disclosed. The method can include determining a number of times data is written to a target track of a storage medium; rewriting data from a track adjacent the target track if the number of times data is written to the target track exceeds a first predetermined threshold; determining a number of times data is rewritten to the adjacent track; copying data from the target track to a first storage location of a media cache if the number of times data is rewritten to the adjacent track exceeds a second predetermined threshold; writing subsequent data designated for the target track to the first storage location of the media cache; and relocating data from the first storage location of the media cache to the target track.

Abstract: Systems and methods are disclosed for improving performance in data storage devices, particularly devices employing shingled magnetic recording. In one embodiment, an apparatus may comprise a data storage medium having multiple tracks with multiple track pitches. In another embodiment, a method may comprise formatting a data storage memory with a first track having a first track pitch, and formatting the data storage memory with a second track having a second track pitch. The method may further comprise formatting the computer readable data storage memory with a set of tracks including the first track arranged to store data in a shingled manner where one track at least partially overlaps an adjacent track, and the second track separating the set of tracks from a third track.

Abstract: An exemplary method for selecting data density values (e.g., bits per inch) and track density values (e.g., tracks per inch) for magnetic recording media having variable bit aspect ratios comprises obtaining a plurality of data density values and a plurality of track density values as a function of a corresponding plurality of bit error rates; determining a data density/track density correlation between the plurality of data density values and the plurality of track density values for at least one Sector Error Rate; and determining a data density capability value and a track density capability value that provides an areal density capability value that satisfies one or more predefined criteria (e.g., a substantially maximum areal density capability value) using the data density/track density correlation.

Abstract: Provided is a tape recording medium including: a base layer having a first surface and a second surface; a first recording layer disposed over the first surface of the base layer and capable of optically recording first data; an imprinted layer disposed between the base layer and the first recording layer; and a second recording layer. The second recording layer is disposed over the second surface of the base layer, contains a magnetic material, and has recorded second data different from the first data.

Abstract: An apparatus includes: a media; a head configured to write data on the media; a read channel, coupled to the head, configured to detect servo data from the media; and control circuitry, coupled to the read channel, configured to: generate a position error signal (PES), associated with a write operation of an aggressor track, from the servo data, compare a first threshold to the PES for detecting a write unsafe condition, compare a second threshold, within the first threshold, to the PES for detecting a write squeeze condition, and control a refresh operation of a victim track based on at least one of the comparisons.

Abstract: To provide enhanced operation of data storage devices and systems, various systems, apparatuses, methods, and software are provided herein. In a first example, a data storage device is presented with storage media comprising a cache storage region and a shingled magnetic recording (SMR) storage region that is divided into burst zones. A storage control system receives write operations and accumulates write data in the cache storage region until a commit threshold condition. Responsively, the storage control system transfers the write data into a burst zone of the SMR storage region, and verifies the write data written into the burst zone once the burst transfer is complete. Responsive to data verify errors in the write data written into the burst zone, the storage control system writes data associated with the data verify errors into an exception location associated with the burst zone.

Abstract: In one embodiment, a method includes determining a stopwrite threshold based on a standard deviation or a variance at a current position error signal sample, and determining whether the current position error signal sample exceeds the stopwrite threshold. Writing is disabled in response to determining that the current position error signal sample exceeds the stopwrite threshold. Writing is enabled in response to determining that the current position error signal sample does not exceed the stopwrite threshold.

Abstract: In preparing to send a write command to store data in at least one Data Storage Device (DSD), a request is sent to the at least one DSD to request environmental information indicating an environmental condition of the at least one DSD. The environmental information is received from the at least one DSD and it is determined whether the environmental information is within a threshold. The write command is sent to the at least one DSD if the environmental information is within the threshold and a precautionary measure is performed if the environmental information is not within the threshold.

Abstract: Dynamic fly height (DFH) controlled read/write heads using multiple heaters have their heater powers set within a range of ratios that allows minimum clearances to be set between the read-gap and the write-gap and the surface of a disk, thereby providing improved touch-down detection. Determining the correct range of power ratios requires varying the ratio to create an adjustable protrusion profile for the read and write elements in the head and measuring values of the ratio and corresponding values of read gap and write gap clearances that create points of minimum clearance. By adjusting the ratio of power supplied to the heaters, different protrusion profiles can be produced, clearance control for sigma reduction can be obtained and read/write readiness and operation consistency and reliability can be improved.

Abstract: A waterfall manufacturing process and apparatus are described for a data storage device. In an aspect, a determination is made during manufacturing of a magnetic storage medium reader system whether a first reader system provides less than a predetermined performance or is nonfunctioning. The reader system includes at least the first reader system and a second reader system with reader elements on the same head. When the first reader system is determined to provide less than the predetermined performance or is nonfunctioning, the reader system is reconfigured during the manufacturing to utilize the second reader system, but not utilize the first reader system, to read the magnetic storage medium. Alternatively, the reader system is reconfigured during manufacturing to read the magnetic storage medium at less than the predetermined performance, or the reader system is situated with a different data storage device configured to function with less than the predetermined performance.

Abstract: An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Abstract: There is provided a method of predicting a noise component associated with a readback signal in a channel from a dedicated servo medium including a data recording layer and a dedicated servo layer. The method including: providing at least one noise prediction module for each of a plurality of types of servo patterns of the servo layer, and predicting the noise component by, for each of a plurality of segments of the readback signal of the data recording layer, using a selected one of the noise prediction modules. In particular, the selected one of the noise prediction module for a segment of the readback signal is selected based on the type of the servo pattern associated with the segment of the readback signal. There is also provided a corresponding noise predictor, a method of detecting data bits from the readback signal, and a hard disk drive system.

Abstract: Systems and methods for reducing operational latency of data storage systems are disclosed. More particularly, a data storage device can perform conditioning operations on inactive zones while the data storage device is idle. When an active zone is the target of a write command, the data storage device can exchange a conditioned inactive zone for the unconditioned target zone. The write operation can be performed immediately on the previously-inactive already-conditioned zone. At a later time, the target zone can be conditioned.

Abstract: Systems and methods for magnetoresistive asymmetry estimation may include, but are not limited to, operations for: receiving a magnetic read head transducer output; computing a mean value of the magnetic read head transducer output; computing a median value of the magnetic read head transducer output; and applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

Abstract: Technologies are described herein for rewriting the initial sectors of a data track on a recording medium of a storage device in order to reduce the occurrence of initial sector weak writes and/or adjacent track erasure. Upon receiving a write command at the storage device, a plurality of sequential segments on the recording media targeted by the write command is determined. The plurality of sequential segments is written to the recording medium, and then data is rewritten to an initial segment of the plurality of sequential segments.

Abstract: The disclosure is related to an apparatus and methods for addressing variations in bit error rates amongst data storage segments. In a particular embodiment, an apparatus includes a controller that detects variations in bit error rates amongst different segments of a plurality of segments in a storage medium. The controller also adjusts a read/write operation parameter according to the detected variations amongst the bit error rates in the plurality of segments.

Abstract: Systems and methods for automating testing of multiple SATA hard drives with multiple motherboards are described herein. In certain embodiments any number of SATA drives may be switchably connected to any number of motherboards, and any number of tests may be performed on combinations of the SATA drives and motherboards without or with only minimal manual intervention between tests. In one embodiment, the system may include an automated selector having a controller adapted to receive a testing instruction and transmit the received testing instruction and a mainboard in communication with the controller. The mainboard may include a logic device to receive the testing instruction from the controller and/or a switch for pairing and unpairing motherboards with SATA storage devices.

Abstract: The application discloses a sensor device to measure friction force at a head-media interface. As disclosed, the sensor device has a transducer element oriented to provide an electrical output responsive to force or strain imparted to the transducer element along an in-plane axis. Sensor circuitry is coupled to the transducer element to process the electrical output to provide an output measure of friction force. In illustrated embodiments, the head includes an actuator element which is powered on/off at an on/off frequency to cyclically protrude a localized portion of the head. The on/off frequency of the actuator is used by the sensor circuitry to detect excitation of the sensor device due to friction force at the head-media interface.

Abstract: A data storage device is disclosed comprising a disk comprising a plurality of tracks, and a head actuated over the disk. A first test pattern having a first polarity is written to a target track, and the first test pattern is read to generate a first read signal. The first test pattern is overwritten with a second test pattern having a second polarity opposite the first polarity, and the second test pattern is read to generate a second read signal. A defect in the target track is detected based on the first read signal and the second read signal.

Abstract: A method, computer-readable medium, and storage device for detecting and compensating for a change in MR-offset in a disk-based storage device. A pattern is written to a track on a disk of the storage device utilizing a read/write head. The read channel of the storage device is then configured as a harmonic sensor and the pattern is read from the track at a specific off-track position of the read/write head. The magnitude of the harmonic sensor is measured during the read, and the change in MR-offset is calculated for the read/write head based on the measured magnitude value and a predetermined transfer function between off-track amount and harmonic sensor magnitude. The change in MR-offset may then be utilized by a servo mechanism of the storage device to correct head positioning during a write operation for the read/write head.

Abstract: A method is disclosed for improved operation of a data storage device such as a hard disk drive, wherein the overhead for data rewriting is reduced or eliminated by the grouping of logical zones in proximity to other zones with similar writing frequencies. Thus cold zones are written near other cold zones, and hot zones near other hot zones, within a multiplicity of realms on the data storage surface. Substantial reductions in FTI writes are achievable in comparison with previous FTI mitigation algorithms.

Abstract: A head-assisted magnetic recording-shingled magnetic recording (HAMR-SMR) type storage device is described that includes a control module and one or more magnetic recording layers partitioned into zones. The control module is configured to write initial data beginning at an initial logical address of a zone. The initial logical address of the zone corresponds to an initial physical address of the zone. Responsive to receiving a command from a host associated with the HAMR-SMR type storage device to reset the zone and write subsequent data, the control module is further configured to reset the initial logical address of the zone to a subsequent physical address of the zone, and after resetting the initial logical address, write the subsequent data beginning at the initial logical address of the zone.

Abstract: A position detector includes detection coils for outputting two sinusoidal signals that have phases shifted from each other by 90 degrees; subtractors for eliminating offset components included in output signals DCA and DSC output from the detection coils; an interpolation calculator for converting the two signals DCA and DSC in which the offset components have been eliminated into position information IP; a radius calculator for calculating a root-sum-square of the two signals DC and DS output from the detection coils; correlation calculators for respectively multiplying a fluctuation component RDA of an output from the radius calculator by the signals DCA and DSC in which the offset components have been eliminated; low-pass filters (LPFs) for extracting DC components of output values output from the correlation calculators; and an outputter for outputting offset components including offset displacement fractions based on output values COMDC and SOMDC output from the LPFs.

Abstract: According to one embodiment, a controller in a magnetic disk drive manages the influence, on a first track on a disk, of data writes to tracks within outer and inner adjacent track ranges, using first and second counters associated with the first track. The first and second counters are indicative of the numbers of data writes to tracks within the outer and inner adjacent track ranges, respectively. Based on the values of the first and second counters, the controller reads data from the first track, and rewrites the read data to the first track.

Abstract: An apparatus, comprising a processor, memory including computer program code, the memory and the computer program code configured to, working with the processor, cause the apparatus to perform at least the following: receiving an indication of an input environment, determining that the input environment negatively affects at least one input mode, determining that the input mode is active, and causing display of an input environment notification is disclosed.

Abstract: An information recording device includes a recording medium with a plurality of data tracks and a controller that stores management information regarding data recorded in a group of adjacent data tracks, the recorded data including first data recorded in a first data track that is partially overwritten by second data subsequently recorded in a second data track that is adjacent to the first data track. The controller recovers management data of the recorded data based on whether or not a sector in the first data track that is adjacent to a sector in the second data track can be read by offset read processing when the sector in the second data track cannot be read by normal read processing.

Abstract: Apparatus and method for adaptively mitigating adjacent track interference (ATI) effects on a data recording medium. In some embodiments, a write count value is accumulated for a first track responsive to successive writes to a second track on the data recording medium. For each of the successive writes, the accumulated write count value for the first track is incremented by a different variable amount based on temperature. The first track is refreshed responsive to the accumulated write count reaching a selected threshold value.

Abstract: Certain exemplary aspects of the present disclosure are directed towards an apparatus in which a data-access head is used to access a sequence of data stored in adjacent ones of multiple tracks of a data-storage device, where the sequence of data includes a stochastic or pseudo-random set of bits and on an adjacent one of the multiple tracks, the sequence of bits is represented in a phase-shifted form. The data access of the multiple tracks bits is used to characterize nonlinear interaction therebetween.

Abstract: Disclosed is a data archive system that executes inspection of a recording quality of an optical disc, estimates a recording quality deterioration factor, and informs it to a user, and a method for estimating the recording quality deterioration factor. The data archive system has a server and a data library device. The server has a whole control part, a data library I/F part, and a recording medium. The data library device has multiple recording media, a recording medium storing part, multiple recording/reproducing parts, and a library control part. The recording medium stores attribute information about the recording medium. The whole control part executes first quality inspection on a first recording medium, executes second quality inspection on a second recording medium, refers to attribute information of the recording media recorded on the information recording medium, and controls so that a factor deteriorating the qualities of the recording media may be estimated.

Abstract: Polarity transitions of a write signal applied to a write coil correspond to first bit boundaries written to a magnetic recording media. A heat signal is applied to heat the magnetic recording media via a heat source while bits are being written. The heat signal includes negative pulses that de-energize the heat source during cooling periods corresponding to the writing of the first bit boundaries. The negative pulses are offset from the polarity transitions by a predetermined time.

Abstract: A magnetic disk device according to an embodiment is provided with a magnetic disk including a recording surface with a plurality of tracks on which data is recorded, a head configured to write the data to the recording surface, and a controller configured to count a write count corresponding to a number of writes by the head, and to perform data refresh when the write count exceeds a threshold. While counting the write count, the controller counts using a first count-up value when the head performs an on-track write, and counts using a second count-up value higher than the first count-up value when the head performs an off-track write.

Abstract: A disk drive is disclosed including a disk having a plurality of sectors, and a head actuated over the disk. A defect threshold is initialized, and a first sector is read to generate a first read signal. The first read signal is processed to detect a defect in the first sector relative to the defect threshold. After detecting the defect, the defect threshold is adjusted and the first sector is reread to generate a second read signal. The second read signal is processed to detect the defect in the first sector relative to the adjusted defect threshold.

Abstract: A method according to one embodiment includes measuring a current position error signal, and calculating a statistical derivative using the current position error signal sample. A kurtosis value is calculated using a current position error signal sample or derivative thereof. A threshold value is adjusted using the kurtosis value. The statistical derivative is compared to the threshold value, and writing is enabled when the statistical derivative does not exceed the threshold value. A determination is made whether to enable or disable writing based on a stopwrite threshold when the statistical derivative exceeds the threshold value.

Abstract: A data processing device includes a memory, an arithmetic circuit that accesses the memory by outputting an access control signal CTRL that controls access to the memory, a first data storage unit that stores first data used when a self-diagnosis is performed, a read-modify-write circuit that generates second data by replacing a part of the first data stored in the first data storage unit with modify data outputted from the arithmetic circuit, and a determination unit that diagnoses a failure of the read-modify-write circuit by comparing the second data with an expected value.

Abstract: A data storage device can include a magnetic rotating disk, a solid state memory, and a controller. The controller is configured to generate a first operational metric which is updated at a first frequency and a second operational metric which is updated at a second frequency different than the first frequency, receive a write command to write data to the magnetic rotating disk, and divert the write command to write data to the solid state memory instead of the magnetic rotating disk when at least one of the first operational metric and the second operational metric indicates that writing data to the magnetic rotating disk may be harmful to the magnetic rotating disk or result in data loss.

Abstract: Systems and methods are disclosed for isolated bands of fractional tracks in data storage devices, particularly devices employing shingled magnetic recording. In one embodiment, a device may comprise a data storage medium including a first data storage area including tracks overlapped in a shingled manner and having a first circumferential portion of a track to store data, a second data storage area, and a guard area disposed between the first data storage area and the second data storage area, the guard area including a second circumferential portion of the track as a partial guard track. In some embodiments, the guard area may include at least one sector in the first circumferential portion of the track, such that at least one sector of the guard area is interposed between data storage sectors of the first data storage area.

Abstract: Devices and/or methods may detect data located in adjacent tracks. A signal representative of a first data unit having a higher signal-to-noise ratio may be detected prior to a signal representative of a second data unit having a lower signal-to-noise ratio, and then may be used to improve the signal representative of the second data unit.

Abstract: Described herein is a method for testing an electronic information storage device having a read and write head includes writing a plurality of pattern periods along a single track of a magnetic recording medium of the electronic information storage device using the write head. The method also includes mapping read head signals for each pattern period across the single track and surrounding regions of the magnetic recording medium. Additionally, the method includes determining a condition of the electronic information storage device based on an average of the read head signals. The condition can include adjacent track degradation of the magnetic recording medium.

Abstract: Systems and methods are provided for evaluating an asymmetry metric. A receiver receives a synchronization signal, a filtered signal, and a reference signal. A processor processes the synchronization signal and the reference signal to obtain a peak indicator signal, identifies a first set of values and a second set of values from the filtered signal based at least in part on the peak indicator signal, and evaluates an asymmetry metric from the first set of values and the second set of values.

Abstract: A method and system for providing format savings in data sectors. The method includes receiving a signal outputted from an analog-to-digital conversion circuit. The method further includes shifting a signal phase of the signal based at least upon a corrected phase at an output of a phase loop and a phase measured when the signal was digitally sampled by the analog-to-digital conversion circuit. The method also includes adjusting a gain of the signal based at least upon a current gain loop correction and a gain correction made when the signal was digitally sampled by the analog-to-digital conversion circuit. Additionally, the method includes adjusting the signal based at least upon an output of a current offset correction and an offset correction made when the signal was digitally sampled by the analog-to-digital conversion circuit. The method also includes outputting an adjusted signal to a sync mark detector.

Abstract: A data storage device with compensation for coercivity variations in a magnetic disk storage medium is disclosed. Two procedures are executed to perform the coercivity compensation. In a first procedure, typically performed prior to writing of data, the coercivity at a number of locations on the disk is measured and stored. A second procedure writes data to locations on a magnetic disk storage medium having varying coercivities. To maintain writing widths within predefined limits, a writing parameter is varied according to a predetermined relationship between the value of the writing parameter and the coercivity. Choices of writing parameter comprise the writing current and fly height. The method may be employed for both data writing and self-servo writing of servo patterns.

Abstract: Methods for measuring media performance associated with adjacent track interference are provided. One such method includes iteratively writing data to a target track for each of a plurality of n frequencies, measuring a first signal amplitude and a first noise for each of the n sectors on the target track, writing an aggressor track pattern proximate the target track, measuring a second signal amplitude and a second noise for each of the n sectors on the target track, calculating a weighted sum for each of the signal amplitude measurements for each of the plurality of n frequencies, and calculating a weighted sum for each of the noise measurements for each of the plurality of n frequencies, and repeating the writing the aggressor track pattern, the measuring the second signal amplitude and the second noise, and calculating the weighted sums for preselected numbers of times.

Abstract: An implementation of a system disclosed herein provides a method of deferring decoding of a data sector received at a read channel of a storage device, in response to determining that a data sector cannot be decoded by a first decoder and storing the data sector for further processing by a second decoder.

Abstract: A computer program product includes a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code being executable by a processing circuit to cause the processing circuit to perform the following process. A data transfer operation is monitored for detecting one or more temps. A backhitch delay is set based at least in part on a post-recovery condition of a tape drive performing a portion of the data transfer operation. A backhitch is caused to be performed. At least one condition of the data transfer operation is altered after the backhitch delay.

Abstract: A read/write channel module including a sampling module configured to sample a read signal corresponding to data stored on a disk. A first preamble is encoded with a first timing recovery pattern on a first track of the disk. The first timing recovery pattern includes a first pattern that changes every x bits. A second preamble is encoded with a second timing recovery pattern on a second track of the disk adjacent to the first track. The second timing recovery pattern includes a second pattern that changes every y bits. A data processing module is configured to process the read signal to remove inter track interference from the read signal based on a difference between the first timing recovery pattern and the second timing recovery pattern.

Abstract: Inter-track interference cancelation is disclosed, including: receiving an input sequence of samples associated with a track on magnetic storage; using a processor to generate inter-track interference (ITI) data associated with a first side track including by performing a correlation between the input sequence of samples and a sequence of data associated with the first side track.

Abstract: Technologies are described herein for utilizing a head heater to test temperature stability of a head of a storage device and to prevent the head from operating in an unstable temperature condition. A first power level may be applied to a head heater of a head in a storage device, the first power level configured to simulate a temperature condition in the head. An instability of the head is determined and the temperature condition and the instability of the head are recorded in a memory. The process may be repeated to develop a range of temperature conditions in which the head exhibits instability. The range of temperature conditions and the head heater may then be utilized to prevent the head from operating in an unstable temperature condition during normal operation.

Abstract: In one embodiment, a microwave-assisted magnetic recording (MAMR) head includes a main pole configured to write data to a magnetic medium using a write magnetic field, a write coil, wherein the write magnetic field is produced by the main pole upon a recording current, Iw, being provided to the write coil, and a spin torque oscillator (STO) positioned near the main pole, the STO being configured to provide a high-frequency assistance magnetic field to the magnetic medium upon a STO drive current, ISTO, being provided to the STO, wherein the STO drive current, ISTO, is ramped-up prior to the recording current, Iw, being provided to the write coil in order to begin a write operation for writing data to the magnetic medium. A method of operation for the MAMR head and an apparatus including the MAMR head are also described according to additional embodiments.

Abstract: According to at least one embodiment, a magnetic disk apparatus includes a disk, a random number generator, a determination module, and a refresh module. The disk includes a plurality of tracks. A random number generator generates a random number within a range of N integers in accordance with writing to a first area of a first track of the plurality of tracks. A determination module determines whether the generated random number includes a predetermined number. A refresh module refreshes a second area of a second track near the first track based on a result of determination of the determination module. The second area corresponds to the first area.