International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies

Atsushi Kanamaru

Takahiro Saito

Hideo Asano

Hiromi Kobayashi

Tadahisa Kawa

Toshio Kakihara

Tetsuo Ueda

Hiroyuki Ono

Akira Kibashi

Hirofumi Saitoh

Koichi Kushida

Donald Joseph Molaro

Jorge Campello De Souza

Hiroshi Uchiike

Takashi Kuroda

Daniel James Colegrove

Masahiko Sato

Kazunari Tsuchimoto

Damien C D Le Moal

Keiji Kobayashi

Hiroshi Oshikawa

Hiromi Nishimiya

Frank Rui-Feng Chu

Takahiro Saitoh

Kelvin Kao

Yuhji Kigami

Takumi Satoh

Tsuguaki Kowa

Takayuki Yamaguchi

Chi-Chen Wu

Masahiko Satoh

A data storage device accepts queued read and write commands that have deadlines. The queued read and write commands are requests to access the data storage device. The deadlines of the queued read and write commands can be advisory deadlines or mandatory deadlines.

Data storage devices accepting queued commands having deadlines

Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.

Disk drive device and method for determining data track format of the disk drive device

Embodiments of the present invention provide a media drive that is intended for reduction in power consumption required for serial communications to/from a host, and a power saving method thereof. In one embodiment, a HDD includes: a cache; a host interface for transferring, to a host, transfer data read out from the cache; a host interface manager that controls the execution of commands so as to generate a transfer unnecessary period during which a command and transfer data need not be exchanged with the host; and a MPU that brings a serial communication part of the host interface into a power save mode during the transfer unnecessary period. The host interface manager determines the optimum data transfer timing of transferring data from the cache to the host on the basis of a transfer rate at which data is transferred to the host, and a read rate at which data is read out from a disk into the cache.

Media drive that creates a transfer unnecessary period, and power saving method thereof

Data in a nonvolatile memory included in a data storage device is rewritten with higher security. According to one embodiment of the present invention, if an error is included in data stored in a nonvolatile semiconductor memory, the HDD rewrites correct data to the nonvolatile semiconductor memory. In particular, during the execution sequence of a write command, the HDD executes rewrite processing of control data stored in the nonvolatile semiconductor memory. More specifically, data is rewritten during a specified period of time that falls within a period of time starting from a start notification of write-data transfer processing that is sent from the HDD to the host, until a command completion notification. Since there is a very small possibility that the power of the host may be interrupted during this specified period of time, it is possible to securely rewrite data.

Data storage device, and method for rewriting data in nonvolatile memory

Embodiments of the invention improve the cache hit ratio of read data. A hard disk drive (HDD) according to an embodiment of the present invention determines whether the read buffer should be used in its entirety or the partial continuous space should be used to read read-data from the magnetic disk. When the HDD determines use of the partial continuous space, the HDD specifies the sub-buffer which is a continuous space wherein the leading-end position and the trailing-end position are coupled to each other, and executes data writing to the sub-buffer in parallel with data reading from the sub-buffer and transmission thereof to the host. The sub-buffer capacity coincides with the data length of the back data.

Data storage device and control method with buffer control thereof

Embodiments of the present invention provide a media drive capable of improving command processing performance by, when a plurality of commands is queued, shortening seek time and rotational latency, and also effectively making use of the shortened period of time. In one embodiment, a HDD includes a queue capable of storing a plurality of commands, and a queue manager for optimizing the execution order of the plurality of commands on the basis of whether or not the execution of each command requires access to a medium. The queue manager determines the execution order so that medium access processing of accessing a disk for execution, and data transfer processing of transferring data between the HDD and a host, are executed in parallel with each other. For example, read processing and transfer processing are executed in parallel with each other. The read processing is adaptive to read out a read command, data of which does not exist in the cache, from the disk into the cache. The transfer processing is adaptive to transfer a read command, data of which exists in the cache, to the host.

Media drive and command execution method thereof

Embodiments of the invention raise the performance of a HDD by controlling the timing of notifying of command completion. In one embodiment, transmission of command completion notifications to a host is managed by a host interface manager. If two data write addresses respectively for two queued commands are adjacent or near to each other, that is, these addresses on the magnetic disk can be accessed without rotational latency, the host interface manager postpones the transmission of a command completion notification (X) concerning the first write command (X). Two command completion notifications (X) and (Y) are performed at a time after the write data (Y) for the next command is transmitted and its write to the medium is completed.

Data transmission control method and storage device

A method and apparatus for efficiently executing a read request issued from a host computer when write requests are cached in a cache memory.

Data storage apparatus, computer apparatus, data processing apparatus, and data processing method

Method for assigning alternative sector, method for reading data, disk drive apparatus, and apparatus for writing/reading AV data

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

The present invention includes a method of reading and writing data on a recording medium, and a system including a disk drive apparatus and a disk drive apparatus controller. According to the method of the present invention, data can be read in the middle of a plurality of write commands provided that the addresses of the read/write data locations do not overlap. This method and system results in improved read/write times.

Method and system of reading and writing data by a disk drive apparatus

A disk storage device is disclosed for avoiding the instantaneous performance degradation as much as possible, and a method for processing a defective sector in such a disk storage device. There is executed a predetermined check related to a function of the disk storage device, preferably at least one of a read test, a write servo test, or a write test, when the disk storage device is in a waiting state where the disk storage device has no access from a host. The read test and write servo test are used to search for a defective sector on a disk and reassign the defective sector. The write test is used to indicate an abnormal condition of a head. Furthermore, the disk storage device includes a detector for detecting the waiting state, and a check logic for executing a predetermined check.

Disk storage device and a method for processing defective sectors in a disk storage device

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 system are disclosed to prevent significant degradation of a data transfer rate in write cache transfer, thereby keeping the minimum data transfer rate high. The initial value T of the virtual buffer full capacity T(t ) is set to F/N (where F is a data capacity of the buffer, and N>1) and it is determined if the amount of write cached data S(t ) reaches the virtual buffer full capacity T(t ) so that write cache transfer is enabled during an S(t )<T(t ) period and if virtual buffer full (S(t )&equals;T(t )) is satisfied, the write cache transfer is inhibited until S(t )<T(t ) is satisfied and the virtual buffer full capacity T(t ) is increased by a predetermined value K from the current one each time disk writing is stopped (each time a write error occurs) while the virtual buffer full is continued, thereby enabling write cache transfer while disk writing is stopped.

Method for controlling write cache transfer and disk unit

A disk drive device comprising a disk-shaped recording medium, having a recording surface on which a plurality of tracks having a predetermined width in a radial direction are defined, said recording surface including a first area wherein a plurality of recording tracks and a plurality of non-recording tracks are located so as to form an alternating pattern along the radial direction of the recording surface. The disk drive device may further comprise: a transducer to record information on the disk-shaped recording medium; a position error detector element to detect position error relative to a target track to be recorded on; an actuator to move the transducer to the target track according to the position error; and an end-of-seek detector, wherein when the transducer is moved to a target track inside the predetermined area the end-of-seek detector determines an end of seek based on whether the position error is less than a first threshold, and when the transducer is moved to a target track outside the predetermined area, the end-of-seek detector determines an end of seek based on whether the position error is less than a second threshold, wherein the second threshold is less than the first threshold.

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Sagamihara, Japan

Atsushi Kanamaru