Abstract: A method involves determining a threshold error rate that will result on data stored on a magnetic disk surface of a disk drive being unrecoverable. The method also involves determining a seek velocity that will overwrite sufficient portions of the data such the data will exhibit at least the threshold error rate. The disk drive performs at least one traversal of the magnetic disk surface with a head of the disk drive that emits an erase field during the at least one traversal at the seek velocity. The at least one traversal sanitizes the data.

Abstract: The technology disclosed herein pertains to a method for determining expected command completion time (CCT), the method including receiving a plurality of position error signals (PESs) for an HDD over a predetermined time period, determining sigma of the plurality of PESs, retrieving upper off-track limits (UOL) for one or more data sectors of the HDD, calculating average number of retrieved sectors (A) between two consecutive occurrences of the |PES|>UOL for the HDD, and determining required number of revolutions (CCT) to collect data based on the average number of retrieved data sectors (A) and a total number of requested data sectors (N).

Abstract: The technology disclosed herein pertains to a system and method for managing write failures in a disc drive. Implementations disclosed herein provide a method including monitoring write fault events per sector for a storage device, in response to a write fault event, updating a write fault repeat count table, wherein the repeat count table tracks a number of write fault repeat counts per sector, comparing a write fault repeat count for a sector to a predetermined threshold write fault repeat count, and in response to determining that the write fault repeat count for a sector is above the predetermined threshold write fault repeat count, performing a write-reassign operation.

Abstract: A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.

Abstract: Systems and methods are disclosed for detecting shingled overwrite errors. When a read error is encountered when reading from shingled recording tracks, a processor may determine whether the read error is an error caused by shingled overwriting. The processor may determine whether the read error is caused by shingled overwriting by determining read signal quality of one or more sectors preceding the read error, such as based on a bit error count or bit error ratio (BER), and comparing the read signal quality to a threshold value. The processor may determine that the read error is caused by shingled overwriting when the read signal quality value is lower than the threshold.

Abstract: A data storage device can have one or more rotating data media with data tracks that are radially disposed from a central spindle. The data tracks may be logically divided into multiple regions while a write strategy is generated with a region module to set a sequence of different regions for future data writes. Receipt of a data write request to the data storage media from a host can prompt the region module to classify the data write request as a sequential or random write in order to intelligently select a region to satisfy the data write request based on the write strategy to maximize data writing consistency for data associated with the data write request.

Abstract: The technology disclosed herein pertains to a method for determining expected command completion time (CCT), the method including receiving a plurality of position error signals (PESs) for an HDD over a predetermined time period, determining sigma of the plurality of PESs, retrieving upper off-track limits (UOL) for one or more data sectors of the HDD, calculating average number of retrieved sectors (A) between two consecutive occurrences of the |PES|>UOL for the HDD, and determining required number of revolutions (CCT) to collect data based on the average number of retrieved data sectors (A) and a total number of requested data sectors (N).

Abstract: The technology disclosed herein pertains to a system and method for managing write failures in a disc drive. Implementations disclosed herein provide a method including monitoring write fault events per sector for a storage device, in response to a write fault event, updating a write fault repeat count table, wherein the repeat count table tracks a number of write fault repeat counts per sector, comparing a write fault repeat count for a sector to a predetermined threshold write fault repeat count, and in response to determining that the write fault repeat count for a sector is above the predetermined threshold write fault repeat count, performing a write-reassign operation.

Abstract: An adjacent track interference (ATI) metric is determined for each of a plurality of regions of a single surface of a magnetic disk. Based on the ATI metrics, each of the regions is assigned a region-specific directed offline scan (DOS) criterion, at least two of the DOS criteria being different from one another. Based on a write count of a track within one of the regions satisfying the associated region-specific DOS criterion, a DOS remediation of the track is performed.

Abstract: The technology disclosed herein pertains to a method for determining expected command completion time (CCT), the method including receiving a plurality of position error signals (PESs) for an HDD over a predetermined time period, determining sigma of the plurality of PESs, retrieving upper off-track limits (UOL) for one or more data sectors of the HDD, calculating average number of retrieved sectors (A) between two consecutive occurrences of the |PES|>UOL for the HDD, and determining required number of revolutions (CCT) to collect data based on the average number of retrieved data sectors (A) and a total number of requested data sectors (N).

Abstract: The technology disclosed herein pertains to a system and method for managing write failures in a disc drive. Implementations disclosed herein provide a method including monitoring write fault events per sector for a storage device, in response to a write fault event, updating a write fault repeat count table, wherein the repeat count table tracks a number of write fault repeat counts per sector, comparing a write fault repeat count for a sector to a predetermined threshold write fault repeat count, and in response to determining that the write fault repeat count for a sector is above the predetermined threshold write fault repeat count, performing a write-reassign operation.

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: The technology disclosed herein pertains to a method for determining expected command completion time (CCT), the method including receiving a plurality of position error signals (PESs) for an HDD over a predetermined time period, determining sigma of the plurality of PESs, retrieving upper off-track limits (UOL) for one or more data sectors of the HDD, calculating average number of retrieved sectors (A) between two consecutive occurrences of the |PES|>UOL for the HDD, and determining required number of revolutions (CCT) to collect data based on the average number of retrieved data sectors (A) and a total number of requested data sectors (N).

Abstract: An adjacent track interference (ATI) metric is determined for each of a plurality of regions of a single surface of a magnetic disk. Based on the ATI metrics, each of the regions is assigned a region-specific directed offline scan (DOS) criterion, at least two of the DOS criteria being different from one another. Based on a write count of a track within one of the regions satisfying the associated region-specific DOS criterion, a DOS remediation of the track is performed.

Abstract: The disclosed technology provides a method that improves CCT in SMR device systems. In one implementation, the method comprises writing data to a shingled magnetic recording (SMR) band in a storage device, determining whether an off-track write has occurred, identifying unsafe written data in response to determining that an off-track write has occurred, determining whether caching space is available upon identifying unsafe written data, continue writing data to the SMR band without a write retry upon determining that caching space is available, and writing unsafe written data to the available caching space. In another implementation, the method comprises receiving a request to repair an encroached track in an SMR band, recovering encroached data to a dynamic random-access memory, determining whether caching space is available, writing the recovered data to the available caching space upon determining that caching space is available, and merging other cached data in the SMR band.

Abstract: Systems and methods are disclosed for reducing adjacent track erasure from write retry operations. In certain embodiments, an apparatus may comprise a circuit configured to abort a write operation while writing to a selected sector of a disc storage medium during a first revolution of the disc storage medium, and mark the selected sector as a temporary bad sector in a mapping table. The circuit may perform a write retry to continue the write operation starting at a next sector contiguously following the selected sector, without attempting to write the selected sector again, during a second revolution of the magnetic disc.

Abstract: A method includes detecting noise in a laser output of a heat assisted magnetic recording device. The noise is converted into an electrical signal including a numerical value. A least significant digit of the numerical value is selected. The least significant digit is concatenated with another least significant digit from another detecting of another noise in another laser output to form a number.

Abstract: A method writing data received from a host device includes determining whether command data of a write command includes metadata, flushing the command data out of a volatile write cache according to a first caching policy responsive to a determination that the command data does includes metadata, and flushing the command data out of the volatile write cache according to a second different caching policy responsive to a determination that the command data does not include metadata.

Abstract: Apparatuses and methods disclosed herein relate to detecting a signal generated by a spin torque oscillator (STO). The signal is outputted, wherein the signal includes a direct current (DC) component, a wide bandwidth noise component, and an STO oscillating radio frequency (RF) component. The signal is filtered, wherein the filtering removes the DC component and the STO oscillating RF component, leaving the wide bandwidth noise component. A value of the wide bandwidth noise component is converted into a binary value, and a bit from the binary value is selected and combined with another bit to form a random number.

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.