International Business Machines Corporation

Lenovo (singapore) Pte. Ltd.

Kazuhiro Ozeki

Hiroshi Itagaki

Hironobu Nagura

Tohru Hasegawa

Yutaka Oishi

Takeshi Ishimoto

Shinobu Fujihara

Katsumi Yoshimura

Takashi Katagiri

Hirokazu Nakayama

When a WORM cartridge is formatted for Tape File System (LTFS) in advance, such as prior to shipment, Linear Tape File System Library Edition (LTFS LE) is expanded by software to reduce consumption of the index partition and to support elimination of the appending of unnecessary data. More specifically, instead of recording metadata in the index partition during normal unmounting, the metadata is recorded in separate local storage such as on hard disk drive (HDD), and the index partition is updated only when the cartridge is ejected from the library. In this way, the present invention is able to significantly reduce the frequency of index partition updates. Because an update occurs only when the user intentionally ejects a cartridge, overflow of the index partition before overflow of the data partition can be prevented.

Support for worm cartridges realized by linear tape file system (LTFS)

Support for WORM cartridges realized by linear tape file system (LTFS)

In a controller of a tape drive, when an error recovery section cannot recover an error detected by an error detecting section, an error-report generation section generates an error report, an error-information acquisition section acquires error information of the tape drive and a cartridge loaded in the tape drive, an error-information exchange section acquires pieces of error information of other tape drives and cartridges loaded in these other tape drives, an error-factor judging section judges whether the error is attributable to the tape drive or the cartridge based on these pieces of error information, an error-report update section updates the error report in accordance with the result of this judgment, and an error-report output section outputs the error report thus updated to a host.

Performing process for removal medium

A device for reading data recorded on a recording medium having multiple tracks, the device including: a receiver that receives designations of a number of data elements to be read; and a determination unit that determines an order of reading the data elements so that, no matter on which track of the tracks each of the data elements is recorded, the data elements are read in an order of recorded locations of the data elements in a direction along the tracks on which the data elements are recorded.

Reading data stored in recording medium

A device, method, and computer program product are provided for migrating pieces of data from a first recording location to a second recording location based on access frequency. The device comprises an obtaining unit for obtaining, for each of the pieces of data, first information indicating the number of times any data has been read from the first recording location after the piece of data is written to the first recording location and second information indicating the number of times the piece of data has been read from the first recording location. Moreover, the device comprises a tracking unit for tracking access frequency with respect to each of the pieces of data using the first information and the second information. Furthermore, the device comprises a determining unit for determining recording positions of each of the pieces of data in the second recording location based on the tracked access frequency.

Device, method, and computer program product for data migration

A method for evaluating data transfer performance within a data recording apparatus is disclosed. The data recording apparatus includes a buffer and a recording medium. Initially, a Pause time P when data transfer between the buffer and a host being stopped temporarily is measured. Then, an ideal Pause time Y is determined. Next, a determination is made whether or not the Pause time P exceeds a sum of the ideal Pause time Y and an allowance a. If the Pause time P exceeds a sum of the ideal Pause time Y and the allowance a, a warning signal is sent to the host.

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Sagamihara, Japan

Kazuhiro Ozeki