International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Akira Kibashi

Hideo Asano

Daniel James Colegrove

Masahiko Sato

Kenji Okada

Takahiro Saito

Hiroaki Suzuki

Atsushi Kanamaru

Hideki Ohzeki

Makoto Takase

Tatsuya Endo

Keiji Kobayashi

Hiromi Nishimiya

Takahiro Saitoh

Kenji Kuroki

Masakazu Sasaki

Takao Matsui

Koji Kurachi

Koichi Arai

Katsumi Suda

Yoshio Yamamoto

Kelvin Kao

Koichi Kushida

Chi-Chen Wu

Hisashi Kakuta

A method and apparatus for providing stream linking in audio/video disk media is disclosed. The present invention sets-up an audio/video stream on a disk drive, uses read and write commands for accessing contiguous data and, given an established stream, establishes a linked stream by sending a linked stream request with the number of a primary stream to the drive. The new stream inherits the beginning and ending addresses of the primary stream. Passed pointer detection is enabled for linked stream pointers passing primary stream pointers.

Method and apparatus for providing stream linking in audio/video disk media

Method and apparatus for providing stream linking in audio/video media

If the number of retries made before data is read successfully reaches or exceeds a predetermined number, the data is saved in spare sectors SS and then data sectors DS which originally stored the data are overwritten. Furthermore, both when data is saved in spare sectors SS and when data is written over data sectors DS, appropriate pointer information in RDM table stored in a reserved area RA including a nonvolatile memory is updated as required.

Recording and playing back device with error correction

An external controller performs a thorough analysis and prediction on true requests from an application to issue a look-ahead request to an HDD or other auxiliary storage. An HDC card is connected to an HDD device which stores data and has a cache memory. The HDC card, which controls the HDD device, includes an access request tracer for tracing a true access request made by an application program executed by a host directly from the application program, a speculation request determination section for determining a speculation request to be expected later based on the traced true access request, and an HDC for issuing the determined speculation request to the HDD device.

Controller device, disk controller, auxiliary storage, computer device, and method for controlling auxiliary storage

A system and method are provided that reduce the amount of data held commonly in both high-ranking and low-ranking cache memories, thereby having each of those cache memories hold data more efficiently. More particularly, a computer system is provided with an HDC card connected to an expansion bus and an HDD unit connected to the HDC card . The HDC card is provided with a disk cache (high-ranking cache memory) and the HDD unit is provided with a disk cache (low-ranking cache memory). The HDC card and the HDD unit exchange select information for selecting a swap mode of each cache memory when the system is started up, thereby selecting different swap modes according to the exchanged select information respectively.

System and method for controlling cache memories, computer system, hard disk drive unit, and hard disk control unit

A method and apparatus for providing passed pointer detection in audio/video streams on disk media. The present invention sets up an audio/video stream on a disk drive, uses read and write commands for accessing contiguous data and provides a pointer system that provides a warning when manipulating the pointers during fast forward and reverse functions that one pointer has passed the other. The position of a first pointer and a second pointer in at least one stream is monitored during a command execution. A determination is made when the positions of the first and second pointers cross to create a passed pointer state. An indicator is set to signal that a passed pointer state has occurred. The passed pointer indicator is then used to prevent anomalous behavior in processing of the at least one stream.

Method and apparatus for providing passed pointer detection in audio/video streams on disk media

A method and an apparatus for predicting the recovery time required until the hard disk drive is restored to a usable state from a stand-by state. The recovery time is a time required until the hard disk drive is restored to a usable state from the stand-by state. Then, the predicted recovery time is reported to the host system. When the host system knows how much time is needed until the disk drive is recovered, it can schedule a task to be completed before the hard disk drive is restarted, thereby scheduling of all the tasks in the host system can be optimized.

Method and apparatus for predicting recovery time of hard disk drive

A method and apparatus for recovering from operation errors arising in an information recording and reproducing unit using a head with a GMR sensor is described. The read and write operations of the unit comprise executing a first error recovery procedure for recovering the operation error, executing a first GMR evaluation procedure for evaluating the performance of the GMR sensor when the operation error cannot be recovered by the first error recovery procedure, and applying a resetting pulse to the GMR sensor in accordance with the first GMR evaluation procedure.

Error recovery in unit using GMR sensor

A disk device and a method are described for reassigning data areas (e.g. sectors) which minimize the reduction in the data transfer rate when alternate data areas are used to replace defective areas. The disk device uses a plurality of data zones with spare areas allocated in each data zone. An alternate area is allocated (a) in the spare area within the data zone where the error occurs and (b) at an angular position offset more than a predetermined angle from a position of the data in which the error occurs. The offset angle allows the device time to seek to the alternate area, read the alternate area and seek back to the area following the defective area within a single rotation of the disk.

Disk device and data reassignment method

A storage device is described which has a plurality of different error recovery routines which are are divided into groups. When an error occurs, specific routines are selected from the groups in accordance with the error type. The selected routines are executed in order. By preferentially executing the selected routines corresponding to the error type, the error recovery rate in the early stages of the error recovery procedure is enhanced.

Storage device and error recovery method executing a plurality of error

A disk drive apparatus and a method for executing an error recovery process for an error caused by thermal asperity is set forth by positioning a disk read/write head in the vicinity of a thermal asperity and then by vibrating the head so that the head hits the foreign matter or protrusion on the surface of the disk causing the thermal asperity. Vibrations in the longitudinal direction are generated in a head by supplying a vibration signal to VCM. The vibration signal is superimposed on a head driving signal. During the vibration process, the head is positioned on a track shifted from a thermal asperity causing track by several tracks in order to hit the thermal asperity by an edge of a head.

Error recovery method and disk drive apparatus to superimpose a

When a sharp change in signal judged due to thermal asperities has appeared, a disk drive apparatus according to the present invention repeats the unidirectional seek operation in a region centered on the belonging cylinder position of the track in which the read error has occurred as one data recovery operation, then scrubs and removes the thermal asperities by putting the component surface around the MR head into positive contact with the asperities, thereby eliminating the fundamental cause of a read error caused by thermal asperities.

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Zama, Japan

Akira Kibashi