International Business Machines Corporation

Globalfoundries Inc.

Industrial Business Machines Corporation

Ernest Stewart Gale

Icko E T Iben

James Mitchell Karp

Lee Curtis Randall

Eiji Ogura

Pamela Ruth Nylander-Hill

Leonard George Jesionowski

Shawn Michael Nave

Michael Philip McIntosh

Kevin Bruce Judd

Randy Clark Inch

David Lee Swanson

Said Abdullah Ahmad

Josephine F Bayang

Nhan Xuan Bui

Robert G Biskeborn

Kevin Dale Butt

Kazuhiro Tsuruta

W Stanley Czarnecki

Jason Liang

Robert Allen Hutchins

Hirokazu Nakayama

Wlodzimierz Stanley Czarnecki

Tsuyoshi Miyamura

Roy Daron Cideciyan

Simeon Furrer

Reed Alan Hancock

Eric Rolf Christensen

Steven Michael Wallace

Dale A Christiansen

Daniel James Winarski

Mark Alfred Lantz

Keisuke Tanaka

Sedat Oelcer

Brian Gerald Goodman

Paul Merril Greco

Mitsuhiro Nishida

Kenji Nakamura

Scott Milton Fry

Khanh V Ngo

Josephine F Kubista

Charles V Polkiewicz

Justin Ryan Cripps

Evangelos Stavros Eleftheriou

Glen Alan Jaquette

Paul Merrill Greco

Alex Chliwnyj

Masayuki Iwanaga

Richard L Bradshaw

Armando Jesus Argumedo

David Michael Davis

Scott Jeffrey Schaffer

Sushama M Paranjape

Stephen C West

John James Gniewek

Richard Alex West

Illarion Borisevich

Charles E Bailey

Josephine Faith Bayang (Kubista)

Carl A Hassell

The present disclosure includes systems and methods for reducing rewrite overhead in a sequential access storage system. The method may comprise writing a data set to a sequential access medium using a magnetic head, wherein the data set comprises a plurality of encoded data blocks, classifying each of the plurality of encoded data blocks on the sequential access medium into one of at least three classes of write quality, and rewriting the encoded data blocks in a rewrite area of the sequential access medium based at least in part on the write quality class. In some embodiments, the at least three classes of write quality may comprise a hard rewrite class for which rewrites are necessary to prevent data loss, a soft rewrite class for which rewrites are desirable but not necessary, and a no rewrite class for which no rewrite is needed or desired.

Selective hard and soft rewrites

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 data storage library system includes a data storage library, at least one environmental conditioning unit, at least one data storage drive retained within the data storage library, and at least one access door for providing access to an interior portion of the data storage library. The system also includes a library controller, wherein the library controller is configured to initiate a service mode prior to and during a service procedure performed within the data storage library, and further wherein at least one operational state within the at least one data storage drive is changed during the service mode. The change in the at least one operational state may be, for example, an increase in temperature within the at least one data storage drive, or the insertion of a data storage cartridge into the at least one data storage drive during the service mode.

Data storage library with service mode for protecting data storage drives

In an approach to adaptive tape calibration criteria based on the number of dead tracks, the number of rewrite occurrences for each dead track on a tape drive is determined. Responsive to detecting that a head is in a dead track state, the number of dead tracks is stored on the tape drive. A calibration threshold is determined, where the calibration threshold includes the number of dead track rewrites and the calibration reference value for a specific tape drive type. Responsive to the number of rewrite occurrences exceeding the calibration threshold while writing a data set, a calibration of the tape drive.

Adaptive tape calibration criteria by number of dead tracks

Provided are a tape drive, tape drive controller, and method for measuring amplitudes of written tracks to determine errors in read and write elements. The write element writes a data pattern and erase pattern to the tape medium to provide the data pattern and the erase pattern on sides of the data pattern. The read element is positioned to measure amplitudes at offsets in the data pattern. The offsets and the amplitudes at the offsets are processed to estimate a maximum amplitude read while the read element is estimated to be positioned entirely in the data pattern and estimate an offset at which the read element reads a fixed percentage of the maximum amplitude. A width of the read element is estimated based on the estimated offset. The estimated width of the read element is outputted to determine whether the estimated width of the read element is acceptable.

Measuring amplitudes of written tracks in a tape drive to determine errors in read and write elements in the tape drive

A data storage library system includes a data storage library having at least one library frame, at least one environmental conditioning unit associated with the data storage library and configured to control one or more interior environmental conditions within the at least one library frame, and at least one access door for providing access to an interior portion of the at least one library frame. The system also includes a library controller configured to initiate a service mode prior to and/or during a service procedure performed within the at least one library frame, wherein the service mode comprises configuring the at least one environmental conditioning unit to adjust the one or more environmental conditions within the at least one library frame toward one or more exterior environmental conditions outside of the data storage library. Optionally, a lock and/or indicator (visual and/or audible) may control access to the interior of the library frames. Associated methods of servicing a data storage library are disclosed.

Data storage library with service mode

In an approach to adaptive tape calibration criteria based on the number of stop writes, the number of rewrite occurrences caused by a stop write is determined for each specific tape drive type. Responsive to detecting a stop write during a write operation, the total number of stop writes is stored on the tape drive. A rewrite calibration threshold is determined, where the rewrite calibration threshold includes the total number of stop writes on the tape drive and a calibration reference value for the specific tape drive type. Responsive to the number of rewrite occurrences caused by the stop write exceeding the rewrite calibration threshold while writing a data set on the tape drive, a calibration of the tape drive is performed.

Adaptive tape calibration criteria by number of stop writes

A data storage library system includes at least one data storage library, the at least one data storage library comprising at least one library frame, wherein the at least one library frame has at least one environmental conditioning unit configured to control one or more environmental conditions within the at least one library frame. The system also includes at least one access door for providing access to an interior portion of the at least one library frame, a library controller, and at least one louver, where the louver may be selectively moveable to control a communication pathway for external air to enter the at least one library frame. In one embodiment, the at least one louver may be controlled by the library controller to automatically open when it is detected that the one or more access doors are opened, and to close the louver when the one or more access doors are closed.

Data storage library with positive pressure system

A method includes determining whether a tunneling magnetoresistance (TMR) sensor is corroded using resistance, amplitude and signal to noise ratio (SNR) measurements of the sensor. A method to determine whether a TMR sensor is corroded includes determining an expected initial resistance value, Rand measuring a resistance value, R, of the sensor. The method includes calculating a ratio of the Rvalue and the expected initial resistance value, Rand determining whether the ratio is in a predefined range for the TMR sensor. In response to determining that the ratio of the sensor is within the predefined range, the method includes outputting an indication that the TMR sensor is corroded. In response to determining that the ratio of the sensor is outside the predefined range, the method includes outputting an indication that the TMR sensor is not corroded.

Setting bias currents and limiting corrosion in TMR sensors

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.

In one general embodiment, a method includes receiving data logically organized into a predetermined number of two-dimensional arrays, each two-dimensional array including a plurality of NS codewords positioned orthogonally to a plurality of WS codewords. The method also includes successively writing each of the NS codewords to a data storage medium. A first NS codeword from a first two-dimensional array is written to the data storage medium prior to starting to write a second NS codeword from the first two-dimensional array. Also, the plurality of NS codewords are protected with a stronger encoding than the plurality of WS codewords.

Logical format utilizing lateral encoding of data for storage on magnetic tape

A tape drive, according to one embodiment, includes: a processor, and logic which is integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to: determine whether a difference between information and corresponding design values is in a range. The information corresponds to how an array of writers write and/or are expected to write to a magnetic medium during shingled recording. Moreover, the logic is configured to: compute, using the information, data describing a lateral writing position to use during writing such that shingled track edges are aligned according to a format in response to determining that the difference between the information and corresponding design values is not in the range.

Aligned shingled writing for magnetic recording media and media having shingle edge positioned tracks

A tape drive-implemented method, according to one embodiment, includes: detecting a read error, and sending one or more instructions to perform a first re-read attempt on a portion of a magnetic tape corresponding to the read error. In response to determining that the first re-read attempt was unsuccessful, a range of tension settings is selected. A range of lateral offsets is also selected. Moreover, one or more instructions are sent to apply each unique combination of a tension setting from the range of tension settings and a lateral offset from the range of lateral offsets. For each of the unique combinations applied, one or more instructions are sent to perform a second phase re-read attempt on the portion of the magnetic tape corresponding to the read error. Furthermore, a determination is made as to whether the second phase re-read attempt was performed successfully for any of the unique combinations.

Behavioral model for dynamic tension compensation

A data storage library system includes at least one data storage library comprising at least one library frame and at least one environmental conditioning unit, the at least one environmental conditioning unit configured to control one or more environmental conditions within the at least one library frame. The system further includes at least one access door for providing access to an interior portion of the data storage library, a library controller, and at least one warning indicator associated with the data storage library and in electronic communication with the library controller. The at least one warning indicator is configured to provide an indication to an operator when the conditions within the data storage library are such that the at least one access door may be opened and when the conditions within the data storage library are such that the access door should not be opened.

Data storage library with interior access regulation

Growing community of inventors

Tucson, AZ, United States of America

Ernest Stewart Gale