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.

Systems and methods for logically organizing data for storage and recovery on a data storage medium using a multi-level format are described. Embodiments include systems and methods for protecting data stored on a data storage medium so that the data may be recovered without errors.

A method for ensuring data quality integrity on a magnetic tape includes the steps of writing object data to the magnetic tape; dividing the object data into a plurality of data chunks; generating a hash tree from the plurality of data chunks, the hash tree being formed in a plurality of levels, the hash tree including (i) a plurality of chunk hashes wherein a separate chunk hash is generated for each of the plurality of data chunks, and (ii) at least one second level hash that is generated from concatenation of at least two of the plurality of chunk hashes; and checking integrity of a first data chunk of the plurality of data chunks by evaluating at least one of the plurality of chunk hashes and the at least one second level hash.

A system includes a read/write module and a caching module. The read/write module is configured to access a first portion of a recording surface of a rotating storage device. Data is stored on the first portion of the recording surface of the rotating storage device at a first density. The caching module is configured to cache data on a second portion of the recording surface of the rotating storage device at a second density. The second portion of the recording surface of the rotating storage device is separate from the first portion of the recording surface of the rotating storage device. The second density is less than the first density.

A storage array includes a plurality of hard disks, where each of the hard disks is divided into a plurality of chunks, and a plurality of chunks of different hard disks form a chunk group by using a redundancy algorithm. The storage array obtains fault information of a faulty area in a first hard disk, and determines a faulty chunk storing the lost data according to the fault information. The storage array recovers the data in the faulty chunk by using another chunk in a chunk group to which the faulty chunk belongs and stores the recovered data in a recovered chunk. The recovered chunk is located in a second hard disk which is not a hard disk for forming the chunk group.

A storage array includes a plurality of hard disks, where each of the hard disks is divided into a plurality of chunks, and a plurality of chunks of different hard disks form a chunk group using a redundancy algorithm. The storage array obtains fault information of a faulty area in a first hard disk, and determines a faulty chunk storing the lost data according to the fault information. The storage array recovers the data in the faulty chunk using another chunk in a chunk group to which the faulty chunk belongs and stores the recovered data in a recovered chunk. The recovered chunk is located in a second hard disk which is not a hard disk for forming the chunk group.

A system includes a read/write module and a caching module. The read/write module is configured to access a first portion of a recording surface of a rotating storage device. Data is stored on the first portion of the recording surface of the rotating storage device at a first density. The caching module is configured to cache data on a second portion of the recording surface of the rotating storage device at a second density. The second portion of the recording surface of the rotating storage device is separate from the first portion of the recording surface of the rotating storage device. The second density is less than the first density.

A disk drive apparatus determines a pattern of bits of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. The magnetic write transducer applies a magnetic field to a recording medium in response to the data signal. A laser power signal is applied to a laser that heats the recording medium while the magnetic field is applied. The laser power signal is modulated based on the pattern of bits. The modulation reduces differences between track widths of recorded marks having different elapsed time values and/or increases a signal-to-noise ratio of the recorded marks having different elapsed time values.

A data storage device can consist of a data storage medium that has a recording surface accessed by a first transducing head suspended by a first actuator and a second transducing head suspended by a second actuator. The first actuator may be configured to access a first region of the recording surface while the second actuator is configured to access a second region of the recording surface. The first and second regions can be separate and non-overlapping.

According to an embodiment, a magnetic disk is provided with a track, and the track is provided with a data sector. The data sector includes a plurality of servo regions in which servo data is written, and a plurality of first data regions. Each of the plurality of first data regions is disposed between two servo regions of the plurality of servo regions. The controller executes a first write operation of writing data sequentially to the plurality of first data regions using the magnetic head. After the first write operation, the controller executes a second write operation of retrying the writing to a second data region in which the write error is detected among the plurality of first data regions, and not retrying the writing to a third data region in which the write error is not detected among the plurality of first data regions.