Patent classifications
G11B20/1866
Codeword interleaving for magnetic storage media
The present disclosure describes aspects of codeword interleaving for magnetic storage media. In some aspects, segments of a codeword are spread or interleaved across multiple sectors of magnetic storage media. Data for one or more codewords may be received by a read channel and, for each codeword, a respective indicator is selected or received. The indicator may indicate which partitions of the multiple sectors that segments of one of the codewords are to be written. The data is then encoded to provide the codewords and segments of the codewords are placed in an interleaver based on the respective indicator corresponding to the codeword. The codeword segments are written from the interleaver to partitions of the multiple sectors of the magnetic storage media. By so doing, codewords may be spread across multiple sectors, such that a loss of a few sectors does not prevent readback and decoding of the codewords.
Codeword Interleaving for Magnetic Storage Media
The present disclosure describes aspects of codeword interleaving for magnetic storage media. In some aspects, segments of a codeword are spread or interleaved across multiple sectors of magnetic storage media. Data for one or more codewords may be received by a read channel and, for each codeword, a respective indicator is selected or received. The indicator may indicate which partitions of the multiple sectors that segments of one of the codewords are to be written. The data is then encoded to provide the codewords and segments of the codewords are placed in an interleaver based on the respective indicator corresponding to the codeword. The codeword segments are written from the interleaver to partitions of the multiple sectors of the magnetic storage media. By so doing, codewords may be spread across multiple sectors, such that a loss of a few sectors does not prevent readback and decoding of the codewords.
Sequential data storage with rewrite using dead-track detection
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. The logic is configured to determine that one or more tracks of the sequential access medium are dead within a sliding window and rewrite a set of encoded data from the one or more dead tracks to one or more live tracks in a rewrite area of the sequential access medium. Other systems, methods, and computer program products are described according to more embodiments.
SEQUENTIAL DATA STORAGE WITH REWRITE USING DEAD-TRACK DETECTION
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. The logic is configured to determine that one or more tracks of the sequential access medium are dead within a sliding window and rewrite a set of encoded data from the one or more dead tracks to one or more live tracks in a rewrite area of the sequential access medium. Other systems, methods, and computer program products are described according to more embodiments.
Sequential data storage with rewrite using dead-track detection
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.
SEQUENTIAL DATA STORAGE WITH REWRITE USING DEAD-TRACK DETECTION
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.
System and method for tape layout optimization
A magnetic tape for use in a tape drive includes a plurality of tracks and a plurality of media defect characteristics. The plurality of tracks are laid out along a length of the magnetic tape, each of the plurality of tracks being configured to receive data that is organized into a plurality of fixed-size subdata sets each including a plurality of codeword interleaves. The data is laid out on the plurality of tracks in accordance with a tape layout allocation strategy as determined by a tape layout module. The tape layout module includes a tape layout optimization system that receives information on the plurality of media defect characteristics, the tape layout optimization system determining the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics; and the tape layout optimization system determining the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves.
Magnetic disk device
A magnetic disk device includes a disk including a plurality of error sectors including a defect, a first track having a first parity sector, and a controller. The controller is configured to, upon receiving a write command to write first data in a first region of a portion of the first track, which is a portion of the first track, first perform an XOR operation on all sectors of the first track other than one or more sectors of the first region and the first parity sector of the first track, and then write the first data in the one or more sectors of the first region, perform a second XOR operation on the one or more sectors of the first region and the result of the first XOR operation, and write the result of the second XOR operation in the first parity sector.
SYSTEM AND METHOD FOR TAPE LAYOUT OPTIMIZATION
A tape layout module for determining a tape layout allocation strategy for laying out data on tape, the data being organized into a plurality of fixed-size subdata sets with each of the plurality of subdata sets including a plurality of codeword interleaves, the tape including a plurality of media defect characteristics, includes a tape layout optimization system including a processor that receives information on the plurality of media defect characteristics. The tape layout optimization system determines the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics. Additionally, the tape layout optimization system can determine the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves. Further, the tape layout optimization system can determine the tape layout allocation strategy by selectively utilizing at least one tape layout parameter.
System and method for tape layout optimization
A tape layout module for determining a tape layout allocation strategy for laying out data on tape, the data being organized into a plurality of fixed-size subdata sets with each of the plurality of subdata sets including a plurality of codeword interleaves, the tape including a plurality of media defect characteristics, includes a tape layout optimization system including a processor that receives information on the plurality of media defect characteristics. The tape layout optimization system determines the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics. Additionally, the tape layout optimization system can determine the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves. Further, the tape layout optimization system can determine the tape layout allocation strategy by selectively utilizing at least one tape layout parameter.