International Business Machines Corporation

Globalfoundres Inc.

Kevin Dale Butt

Paul Merril Greco

Ernest Stewart Gale

Pamela Ruth Nylander-Hill

Roy Daron Cideciyan

Simeon Furrer

Takashi Katagiri

Eiji Ogura

Randy Clark Inch

Mark Alfred Lantz

Kevin Bruce Judd

Steven Michael Wallace

Dale A Christiansen

Paul Merrill Greco

Yuhko Mori

Leonard George Jesionowski

Louie Arthur Dickens

Keisuke Tanaka

Hirokazu Nakayama

Masayuki Iwanaga

Paul Joseph Seger

Jose G Miranda Gavillan

Michael E Starling

Khanh V Ngo

Shawn Owen Brume

Yun Mou

Laurence William Holley

Nancy Vedder Ryson

Daniel James Winarski

Glen Alan Jaquette

Yutaka Oishi

James Mitchell Karp

Scott Milton Fry

Olive Paige Faries

Tajashi Katagiri

Yuhjo Mori

Antonio Y Pacheco

Mechanisms are provided to receive encoded header information stored on a tape of a tape drive, wherein the encoded header information has been generated by: generating, for a plurality of tracks of the tape of the tape drive, a header information in a plurality of symbols, wherein the plurality of symbols is comprised of a first set of symbols and a second set of symbols, wherein the first set of symbols include identical information across all tracks of the plurality of tracks, and wherein the second set of symbols are configurable to include different information across all tracks of the plurality of tracks; and modifying, for writing to the tape of the tape drive, the first set of symbols of the plurality of tracks to include parity information corresponding to information included in the second set of symbols of the plurality of tracks. The received encoded header information is decoded.

Header decoding mechanism for tape storage

A method for characterizing a magnetic recording tape, according to one approach, includes measuring, using a magnetic head having servo readers of known pitch, a servo band difference at various locations along a length of a magnetic recording tape. The servo band difference measurements and/or derivatives thereof are stored in association with the magnetic recording tape. This procedure creates a characterization of the magnetic recording tape that is useful for assessing aging of the magnetic recording tape, as well as improving subsequent reading and/or writing operations.

Management of head and media dimensional stability

A methodology that enables, for example, tape drive operation at lower SNR and/or reduced rewrite area uses a first threshold T and a second threshold r for a rewrite condition. Codeword interleaves (CWIs) in a data set are written onto a plurality of simultaneously-written parallel tracks of a magnetic recording medium, read back and error correction decoded. A determination is made as to whether at least one of the Cor C' codewords in each decoded CWI contains more byte errors than the second threshold r of the rewrite condition. A number of CWIs in a rewrite buffer are according to the following criteria: b&#x2032;=b&#x2212;T when bis greater than the first threshold T, and b&#x2032;=0 when bis less than or equal to the first threshold T.

Magnetic tape device capable of selecting codeword rewrite based on determined threshold

An apparatus, according to one embodiment, includes a magnetic head having servo readers of known pitch, a drive mechanism for passing a magnetic recording tape over the magnetic head, and a controller electrically coupled to the magnetic head. The controller is configured to measure, using signals from the magnetic head, a servo band difference at various locations along a length of the magnetic recording tape. The controller is also configured to cause storage of servo band difference information about the servo band difference measurements in association with the magnetic recording tape.

A computer-implemented method according to one embodiment includes identifying code word interleaved (CWI)-4 entries to be re-written to a data storage cartridge, selecting a subset of the CWI-4 entries to be included within a first CWI-4 set, where a plurality of the CWI-4 entries within the subset are associated with a single sub data set (SDS), and re-writing the first CWI-4 set to the data storage cartridge.

Prioritized sourcing for efficient rewriting

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

An apparatus configured to characterize a magnetic recording tape of a tape cartridge, according to one embodiment, includes a magnetic head having servo readers of known pitch, a drive mechanism for passing a magnetic recording tape over the magnetic head, and a controller electrically coupled to the magnetic head. The controller is configured to measure, using signals from the magnetic head, a servo band difference at various locations along a length of the magnetic recording tape of a tape cartridge. The controller is also configured to store the servo band difference measurements and/or derivatives thereof in association with the tape cartridge.

A method for characterizing a magnetic recording tape of a tape cartridge, according to one approach, includes measuring, using a magnetic head having servo readers of known pitch, a servo band difference at various locations along a length of a magnetic recording tape of a tape cartridge. The servo band difference measurements and/or derivatives thereof are stored in association with the tape cartridge. This procedure creates a characterization of the magnetic recording tape that is useful for assessing aging of the magnetic recording tape, as well as improving subsequent reading and/or writing operations.

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.

Various embodiments for improving tape drive efficiency using a processor device are provided. In one embodiment, a method comprises aggregating one of records and filemarks, the aggregating restricted to being performed only on read operations, from a plurality of data segments into at least one single data segment, including sequentially aggregating the one of the records and filemarks into the at least one single data segment.

Tape drive buffer utilization

A method according to one embodiment includes monitoring a plurality of parameters relating to operation of a tape drive to collect data from the operation of the tape drive. A specification of one or more of the parameters to log during one or more collection windows is received. At least some of the data collected from the operation of the tape drive is logged to a memory during the one or more collection windows, where the at least some of the data collected is stored in a plurality of fields. The method further includes dynamically overlaying one or more of the fields with data corresponding to the one or more specified parameters.

Extended diagnostic overlay control for tape storage devices

In one embodiment, a tape drive includes a drive buffer, a processor, and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to: receive a list including: user data segments recorded on tape media, wherein the user data segments are arranged in the list according to a predetermined order, and information associated with each user data segment, wherein the information includes a description of a physical location of each of the user data segments on the tape media. The logic is further configured to cause the processor to locate each of the user data segments on the tape media according to the order in the list, read each of the user data segments from the tape media according to the order in the list, and write each of the user data segments to a buffer according to the order in the list.

Reducing elapsed time to access data from a storage medium during a recall operation

A technique for providing end-to-end data protection while supporting multiple cyclic-redundancy-check (CRC) algorithms includes receiving a data block protected by a first CRC. The first CRC is generated using a first CRC algorithm. The integrity of the data block is checked using the first CRC and the first CRC algorithm. A second CRC for the data block is then computed using a second CRC algorithm different from the first CRC algorithm. The data block, first CRC, and second CRC are stored on a storage medium, such as magnetic tape.

End-to end data protection supporting multiple CRC algorithms

Records or filemarks read from data segments are aggregated into at least one single data segment. The records and the filemarks are padded at an end of the one single data segment, such that the padding of the end of the one single data segment is less than padding of the one of the records and filemarks in the plurality of data segments.

A method, system and computer-usable medium are disclosed for reordering User Data Segment (UDS) lists to reduce seek times when accessing data stored on tape media. A host application sends a list of UDSs to a target tape drive and requests the tape drive to reorder the list to provide better performance. An ordered list of target User data Segments to retrieve from a target tape media is received. Information related to the location of each UDS on the target media is processed to determine its corresponding physical position on the tape media. The resulting physical positions are then processed to generate a reordered UDS list, where the order of the User Data Segments is reordered according to their physical location on the target tape media. The reordered list of User Data Segments is then used to perform seek, reposition and read operations to read User Data Segments from the tape media.

Growing community of inventors

Tucson, AZ, United States of America

Kevin Dale Butt