International Business Machines Corporation

Toshiyuki Shiratori

Kohei Taguchi

Hiroshi Itagaki

Glen Alan Jaquette

Takashi Katagiri

Hirokazu Nakayama

Paul Merrill Greco

Hironobu Nagura

Toshimi Ataku

Yutaka Oishi

James Mitchell Karp

Brian Gerard Goodman

Terue Watanabe

Katsuyoshi Katori

Tomoaki Kimura

Mark Edward Hill

Yuuji Kibuse

Mechanisms are provided, in a storage system controller of a storage system, for writing data to a storage medium. The storage system controller receives a write request to write a block of data to the storage medium. The write request does not specify a location on the storage medium to which to write the block of data. The storage system controller determines a current position of a write mechanism of the storage system relative to the storage medium and determines a location on the storage medium to write the block of data based on the current position of the write mechanism. The storage system controller sends a notification to a host system identifying the location of the block of data on the storage medium as determined by the storage system controller. The writing mechanism writes the block of data to the determined location on the storage medium.

Data storage mechanism using storage system determined write locations

A tape recording device, method, and computer program product are provided for performing operations of position movement, reading, and writing on a tape medium, and receiving a series of commands from an upper-layer device. The tape recording device includes a buffer for temporarily storing data related to the reading and an append write, a tape for recording the data stored in the buffer, a reading and writing head for reading data from the tape into the buffer and writing the data onto the tape, control means for reading data from a designated position of the tape and storing the data in the buffer, and for writing the data stored in the buffer onto the tape from a written data end position in response to an append write command, and a non-volatile memory for storing data stored in the buffer in response to an append write command.

Linear recording device for executing optimum writing upon receipt of series of commands including mixed read and write commands and a method for executing the same

A controller for controlling interrupt processing in a multiple-interrupt system is provided. The controller includes multiple watchdog timers (WDTs), each provided for each of interrupt priorities. The controller includes interrupt priority selectors, each of which receives each interrupt request signal and outputs an activation signal to a corresponding WDT according to the priority of the interrupt request signal. The controller includes an interrupt processing circuit, which when a WDT has timed out, outputs, to a processor, an interrupt request signal having a priority one or more levels higher than the priority corresponding to the WDT. When multiple causes of interrupt are assigned to one of the interrupt priorities, the interrupt processing circuit gives priority to an interrupt request signal caused by the timeout of a WDT lower in priority level than the interrupt priority to detect that an abnormal operation has occurred in interrupt processing having the lower level priority.

Detection of abnormal operation caused by interrupt processing

An apparatus according to one embodiment includes a head, a controller coupled to the head, and logic integrated with and/or executable by the controller. The logic is configured to receive a series of commands, the series of commands including mixed read, overwrite, and append write commands, cause reading of data from a specified position of a tape using the head and storing the data in a buffer in response to a read command; and cause writing of data stored in the buffer starting from an appended data end position of the tape in response to an append write command.

Linear recording executing optimum writing upon receipt of series of commands including mixed read and write commands

Provided is a method for recording data to a tape medium in such a manner as to achieve the easy management of mutually related multiple data pieces. First data and second data continuously received as a file from a higher level apparatus are accumulated in multiple buffer segments in the form of multiple successive data sets. A data structure is determined for each of the accumulated data sets. Management information indicating a result of the determination is added to the data sets, and the data sets and the management information thereof are stored into the tape medium.

Data recording method for storing first data and second data into a tape medium

A method is provided according to one embodiment, which executes an optimum writing method even when overwrite is intervened between mixed read and write operations. In response to receiving an overwrite command while executing the mixed operations, which writes to a predetermined tape position, when a tape position to overwrite on is encountered before the append-written data ending position of the tape (tape EOD), the overwritten tape position is regarded as the append-written data ending position of the tape (tape EOD) to update the tape EOD by the overwritten tape position. When a tape position to overwrite is encountered after the append-written data ending position of the tape (tape EOD), the overwritten tape position is updated by the append-written data ending position of a non-volatile memory (non-volatile EOD). The updating the EODs enhances the performance of the mixed read and write operations even when an overwrite command is intervening.

A tape drive is provided, which executes an optimum writing method even when overwrite is intervened between mixed read and write operations. When an overwrite command is received while executing the mixed operations, which writes to a predetermined tape position, when a tape position to overwrite on is encountered before the append-written data ending position of the tape (tape EOD), the overwritten tape position is regarded as the append-written data ending position of the tape (tape EOD) to update the tape EOD by the overwritten tape position. When a tape position to overwrite is encountered after the append-written data ending position of the tape (tape EOD), the overwritten tape position is updated by the append-written data ending position of a non-volatile memory (non-volatile EOD). The updating the EODs enhances the performance of the mixed read and write operations even when an overwrite command is intervening.

Linear recording device for executing optimum writing upon receipt of series of commands including mixed read and write commands and method and program thereof

Data recording and reading device and method

In a controller of a tape drive, when a command processor receives a command for moving to the end of data ('EOD') or the like, an operation signal output unit suspends the moving of a tape and a cartridge memory ('CM') input/output unit stores therein a state of the tape in which the moving has been omitted. Then, when the command processor receives a command for writing data in this state, the CM input/output unit writes the data to a cartridge memory. Subsequently, for example, when a head passes a proper position at which the data should be actually written to the tape, the CM input/output unit reads the data from the cartridge memory, and the channel input/output unit writes the data to the tape at the proper position.

Apparatus for controlling writing data and method for the same

A tape recording apparatus is configured for sequentially recording files when receiving a command to write the files from an external host. The tape recording apparatus includes a buffer for temporarily storing the files, a tape on which the files are recorded, a writing device for writing the files stored in the buffer on the tape, and a writing control device for performing control of sequentially writing the files stored in the buffer on the tape one by one. The writing control device memorizes designated delimiter positions when delimiter position designation commands are received from the external host, the delimiter position designation commands designating the delimiter positions of the files to be sequentially written.

Tape recording apparatus and method

The present invention enhances the capability to specify a recorded position of designated data, even when a tape medium is run at high speed. A controller of a tape drive includes: a data set generator for generating a data set; a metadata generator for generating metadata including the number of records in the data set and the like; and a writing unit for writing the data set to the tape medium with a high recording density, and writing the metadata to the tape medium with a low recording density. The controller also includes: a movement controller for receiving a record number of a designated record; a reading unit for obtaining the number of records and the like included in the metadata read by running the tape medium at high speed; and a comparison unit for determining whether or not to read the data set by lowering the speed of the tape medium to R/W speed, in comparison with the record number received by the movement controller and the number of records and the like obtained by the reading unit.

Apparatus and method for writing and reading data to and from tape medium

Provided are a method, system, removable storage cartridge, and article of manufacture for validating an encryption key file on a removable storage media. Copies of an encryption key file are written to multiple locations on a removable storage media, wherein data is encrypted and decrypted using an encryption key included in the encryption key file. A validation operation is performed on the copy of the encryption key file at one of the key locations, wherein the key locations comprise the locations on the removable storage media to which the encryption key files were written. In response to the copy of the encryption key file not validating, a command is sent to cause the data and valid copies of the encryption key file to be rewritten to a new storage media.

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Tokyo, Japan

Toshiyuki Shiratori