International Business Machines Corporation

Schlumberger Technology Corporation

Nec Display Solutions, Ltd.

Nec-mitsubishi Electric Visual Systems Corporation

Globalfoundres Inc.

Takashi Katagiri

Yutaka Oishi

Yuhko Mori

Hirokazu Nakayama

Pamela Ruth Nylander-Hill

James Mitchell Karp

Hiroshi Itagaki

Atsushi Abe

Motoko Oe

Paul Merril Greco

Scott Milton Fry

Kevin Dale Butt

Hironobu Nagura

Setsuko Masuda

Katsumi Yoshimura

Yutaka Ooishi

Masakatsu Murata

Keisuke Tanaka

Kazuhiro Tsuruta

Yohichi Miwa

Toshiyuki Shiratori

Mitsuhiro Nishida

Hisato Matsuo

Izuru Narita

Yumi Mori

Rika Nagahara

Yoshikuni Murakami

Noriko Yamamoto

Tomohiro Nakagawa

Terue Watanabe

Paul Merrill Greco

Eiji Tosaka

Shinobu Fujihara

Kazuo Yoshioka

Hideki Tanizoe

Miyuki Tachibana

Kazuhiro Ozeki

Yasuhiro Arakawa

Hiroki Iwataka

Denis Syresin

Atsushi Oshima

Yoshiyuki Shirasaki

Kazuaki Takamoto

Hiroshi Akima

Atsush Abe

A system may obtain orthogonal pairs of acoustic waveforms obtained by a rotating downhole acoustic tool. The downhole tool may include an acoustic transmitter and an acoustic receiver. A computing device communicatively coupled to the downhole tool that instructs the transmitter to generate the various waveforms detected by the acoustic receiver and store the various waveforms in a buffer. Each waveform of a subset of the various waveforms oriented in a similar direction may be stacked to generate a composite waveform with reduced noise. The computing system may determine an orthogonal pair of waveforms based on the composite waveform and remaining waveforms.

Systems and methods for acquiring orthogonal pairs of waveforms for acoustic well logging

There is provided a tape recording apparatus system capable of improving writing performance and maintaining tape recording density, for a multiple data writing request accompanied by a lot of synchronization requests from a host. The system is a tape storage system including two or more tape drives each of which has a tape mounted thereon and is provided with a buffer divided in fixed-length segments, and connected to a host that sends multiple data and a synchronization request at a predetermined timing to these tape drives. This tape recording system is provided with: a tape drive connected to the host, receiving the multiple data sent from the host, and, when the segment of the buffer is accumulated and filled with data, writing the accumulated data onto a tape; and another tape drive connected to the tape drive, receiving the multiple data sent from the host via the tape drive, and dumping a predetermined number of data accumulated in the segments onto a tape at a timing of receiving the synchronization request.

Tape storage system including at least two tape storage apparatuses for improved writing of data to be synchronized

A computer program product for implementing write procedures using an estimated best setting in a first run, the computer program product comprising a computer readable storage medium having program instructions executable by a tape drive to cause the tape drive to perform a method comprising: receiving, at the tape drive, a request for a write operation to be performed in the tape drive; determining, by the tape drive, a capacity margin ratio of the tape drive; determining an optimum a write procedure based at least in part on the capacity margin ratio; and invoking the optimum write procedure in response to determining the optimum write procedure. The optimum write procedure is selected from the group consisting of: a backhitch write procedure, a same wrap backhitchless flush (SWBF) write procedure, and a recursively accumulating backhitchless flush (RABF) write procedure.

Write procedure using estimated best setting in first run

A method for detecting at a migration destination medium a change in data during media migration between write once read many (WORM) media according to one embodiment includes writing data for WORM from a migration source medium to the migration destination medium; holding an identifier (ID) of the source medium in a non-user storage area in the destination medium; and holding information indicating a feature of the data in the non-user storage area.

Detecting tampering of data during media migration, and storage device

In one embodiment, a method includes writing a file into a data partition of a tape medium. The method also includes storing a high resolution tape directory (HRTD) having location information of data in the data partition as part of end of data (EOD) of the index partition. The storing the HRTD as part of the EOD of the index partition includes requesting movement of the tape medium to the index partition in order to update an index file after changes have occurred to data in the data partition, and writing an updated index file into the index partition concurrent to writing an updated HRTD into the EOD of the index partition.

High resolution tape directory (HRTD) stored at end of data in an index partition

In one embodiment, a system includes a processor configured to execute logic, the logic being configured to read a plurality of data sets, each data set including a plurality of portions which combine together to wholly form the data set, and reread at least a first uncorrected data set using a different setting in an error recovery procedure (ERP) when an error in the first uncorrected data set is not correctable using C2-ECC or an error in any portion of the first uncorrected data set is not correctable using C1-ECC. Other systems and methods for reading data from tape using a reconstructive ERP to reduce backhitches are presented according to more embodiments.

Reconstructive error recovery procedure (ERP) for multiple data sets using reserved buffer

A method of reducing power consumption of a buffer for cache in a tape drive connected to a host in a communicable manner, according to one embodiment, includes detecting a transfer rate of data from the host or to the host, and determining a writing or reading rate of data to or from a tape based on the data transfer rate. A determination is made as to whether predetermined conditions including the data transfer rate, the data writing or reading rate, and a capacity of a buffer are satisfied, where the buffer includes at least two buffer areas. At least one of the buffer areas is selected when the predetermined conditions are satisfied. The selected buffer area is switched to a power saving mode.

Reduction of power consumption of a buffer in tape drive

In one general embodiment, a tape drive system includes: a read channel; a write channel; logic configured to receiving a request for a write operation to be performed in a tape drive; logic configured to determine an optimum a write procedure in response to receiving the request, the determining being based on expected writing times of each of a plurality of write procedures and an expected transaction size of a next write operation; and logic configured to invoke the determined optimum write procedure in response to determining the optimum write procedure.

A computer program product includes a computer readable storage medium having program instructions executable by a tape drive to cause the tape drive to perform a method comprising: receiving, at the tape drive, a request for a write operation to be performed in the tape drive; determining, by the tape drive, an expected transaction size of a next write operation; comparing, by the tape drive, the expected transaction size of the next write operation to each of a first transaction size threshold and a second transaction size threshold in response to receiving the request; determining, by the tape drive, an optimum a write procedure based at least in part on the comparison; and invoking, by the tape drive, the optimum write procedure in response to determining the optimum write procedure.

In one embodiment, a method includes writing a file into a data partition of a tape medium, writing a pointer of the written file in an index partition and creating a high resolution tape directory (HRTD) including detailed location information of data in a data partition. The method also includes storing the HRTD as part of end of data (EOD) of the index partition in response to a tape cartridge housing the tape medium being unloaded. The storing the HRTD as part of the EOD of the index partition includes requesting movement of the tape medium to the index partition in order to update an index file after changes have occurred to data in the data partition, writing an updated index file into the index partition concurrent to writing an updated HRTD into the EOD of the index partition, and requesting for the tape cartridge to be unloaded.

In one general embodiment, a method includes receiving a request for a write operation to be performed in a tape drive, determining an expected transaction size of a next write operation, comparing the expected transaction size of the next write operation to each of a first transaction size threshold and a second transaction size threshold in response to receiving the request, determining an optimum a write procedure based at least in part on the comparison, and invoking the optimum write procedure in response to determining the optimum write procedure, wherein the first transaction size threshold is greater than the second transaction size threshold, and wherein the optimum write procedure is selected from the group consisting of: a backhitch write procedure, a same wrap backhitchless flush (SWBF) write procedure, and a recursively accumulating backhitchless flush (RABF) write procedure.

A first data group in an access sequence is selected. A distance from a current position of the tape medium is set to be a logical distance value, determined by a calculation function, that is substituted for the physical distance value for the data groups that are located in the specified regions as compared with other data groups located in the alternative specified regions. A second data group in the access sequence is selected. The logical distance value is then determined by multiplying a coefficient based on a physical positioning of each of the data groups in the tape medium, and a percentage of those of the plurality of data groups that have already been selected as the first data group and the second data group.

Reducing total seek time for determining an access sequence of data stored on a tape medium

A method for dynamically changing a buffer threshold in a tape drive, according to another embodiment, includes monitoring a history of sizes of data transactions between sync commands, the data transactions being from a host to a tape drive, determining that a next sync command is expected to be received relatively sooner or relatively later based on the history of data size transactions, writing buffered data to a magnetic recording tape in response to determining that the next sync command will be received relatively sooner, and increasing a buffer threshold for delaying writing to the magnetic recording tape in response to determining that the next sync command will be received relatively later. A computer program product according to one embodiment includes a computer readable storage medium having program code embodied therewith, the program code readable/executable by a processor to perform the foregoing method.

Dynamically changing a buffer flush threshold of a tape drive based on historical transaction size

An apparatus, computer readable medium device, and method for controlling transportation of a tape medium. A determination is made whether to execute a backhitch operation in response to writing a data set to tape from the buffer. If not, a determination is made whether a transaction size at which data is transferred from the buffer to the tape is less than a buffer size. If so, then a determination is made of a a new speed and whether a current speed is different from the determined new speed. If so, then a backhitch is initiated.

Apparatus and method for controlling transportation of tape medium

The present invention provides a search method used to search for the reading order of a plurality of recording groups when the plurality of recording groups written on tape are continuously read by a tape drive which manages data on tape in recording units having a fixed data length for each recording. This search method includes the steps of: receiving information on a plurality of tape groups to be read; and sorting the plurality of recording groups to be read so the reading time is shortened. In the sorting step, the time required to sort the plurality of reading groups is reduced by combining two or more recording groups into a single object to be sorted in the sorting step when at least two or more contiguous recording groups have been assigned to the same region or are assigned across adjacent regions among the plurality of regions.

Reading order search method and program for recording

Growing community of inventors

Yokohama, Japan

Takashi Katagiri