Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Ricoh Company, Ltd.

Masahiro Mizuno

Hiroshi Baba

Hitoshi Yamamoto

Shiro Ogura

Kazuhiko Ito

Toshio Matsumoto

Akira Ogawa

Kazuhiko Itoh

Takashi Fujita

Koichi Kudo

Tomoaki Hayashi

Masayuki Sunaoshi

Tsuyoshi Nagasu

Kazuo Ito

Norihiko Ikoma

Mitsunobu Gohda

Keizo Hama

Sosuke Nambu

Shirou Ogura

A power generation control device includes:

Power generation control device for vehicle

For the high-speed data access machine, data is distributed in a plurality of hard disk drives coupled to slave processors to achieve ever-higher data reliability and maintenance. One master processor is provided with a plurality of slave processors, each of which is coupled to two hard disk drives containing the same data. A synchronous signal permits two hard disk drives to operate in synchronous rotation in half-a-turn phase difference from each other. The hard disk controller writes the same data in both hard disk drives but reads data from whichever hard disk drive requires less access time to obtain the data. A plurality of hard disk drives holding exactly the same data improves data reliability. Also, by rotating a plurality of hard disk drives in different phase, the rotational delay in data access is cut by half.

Data access from the one of multiple redundant out-of-sync disks with

A data storage managing system and method in which a HOST system obtains operation information of a storage device from a system connected to a network without the need for a specific device driver are disclosed. When disks shared between systems connected to the network are managed by a disk manager, monitoring and control information for the shared disks may be accessed by a file access command of the operating system on the HOST system. An operation information storage device is formed in a file format which can be accessed by a file access command of the operating system on the HOST system and the HOST system reads the operation information of the storage devices stored in the operation information file according to the file access command. The information to control the operation of the storage devices is written in the operation information file according to the file access command. The disk manager controls the operation of the storage devices according to the operation information of the operation information file.

Method and system including operation information accessible by a system

A data storage system in which system activation is performed in cooperation with two host systems sharing a data storage system. A determination unit determines which of the two host systems makes access to the data storage system. A system access control unit controls access to the data storage system from the host systems to prevent competition between the host systems. Each of the host systems indicates completion of system activation to the other host system.

Shared data storage for two hosts with a storage manager that permits

The present invention relates to an arrayed recording apparatus having spare devices for replacing faulty disk drives. Each of the SCSI controllers in the arrayed recording apparatus connects to a driver/receiver and further connects to spare disk drives. Each of the SCSI controllers accesses the spare disk drive by setting a receive/enable signal effective to the driver/receiver. Unused ID numbers are assigned to the spare disks. If a disk drive develops a fault, the RAID controller RC requests the SCSI controller to replace the faulty disk drive with the spare disk drive. It is possible to attain the function of the hot stand-by system without comprising a specific spare controller.

Arrayed recording apparatus with selectably connectable spare disks

A transmission monitoring and controlling apparatus is provided between a first system and a second system. The transmission monitoring and controlling apparatus monitors information transmitted through a Fibre Channel. Then, a back controller analyzes the monitored information and stores the information in a controlling memory based on the analysis. For example, when the first system writes data on the second system, the back controller stores the data in the controlling memory. Therefore, even if a failure has occurred in the second system, the transmission monitoring and controlling apparatus is able to read the data from the controlling memory and send the data to the first system instead of to the second system.

Transmission monitoring and controlling apparatus and a transmission

Embodiments of the present invention provide a data storage system that reduces a load of a data bus for connecting a HOST system with the data storage system. The data storage system includes a disk manager connected to the HOST system by a SCSI BUS, connected to a disk control unit by an RS PORT and connected to disk enclosures and a fan unit by a Serial BUS. The disk manager monitors operation of the disk control unit and disk enclosures and transmits results to the HOST system. In addition, control commands of the HOST system to the disk enclosures are executed via the disk manager.

Data storage system and storage managing method

Distributed database system having master and member sub-systems

In case of consecutive transmission of a large amount of data such as dynamic image data, a multi-media storage system of the invention generates and transmits data stored in a faulty disk drive when one of a plurality of disk drives being faulty caused by an internal calibration or an error of the disk drive and the faulty disk drive does not respond within a predetermined length of time set in a timeout table. The multi-media storage system cancels an access to the faulty disk drive, generates data to be read from the faulty disk drive based on data stored in the other disk drives of the plurality of disk drives and the redundant data and continues to transmit data.

Multi-media storage system

A read unit 400 which governs reading of data and a write unit 500 which governs writing of data are located separately in a RAID unit 300 which controls array type magnetic disk units. To read data from magnetic disk units 800, a control circuit 600 uses the read unit 400 to read data through an HDD control unit 700. To write data, the control circuit 600 uses the write unit 500 to write data into the magnetic disk units 800. Since the read unit and write unit are provided separately, processing performance improves.

Recording system having a redundant array of storage devices and having

The present invention relates to an arrayed recording apparatus with reduced writing time. Various devices are used to write data without redundant data and to update the redundant data more efficiently during idle time. In one embodiment, a temporary write track is provided for each cylinder. When data are read, updated and re-written, the data are re-written to the temporary write track. Since the re-writing does not require a full disk rotation, the writing occurs quickly. Data in the temporary write track are relocated into the disk during an idle state, without being synchronized. Additionally, corresponding blocks in data areas can be used for writing data rather than a specified temporary write track. In order to improve re-writing time, the rotation of the disk drives can be synchronized to avoid full rotations between reads and writes, or cache memories for each disk can be used. When data is accessed from a host computer in a first unit size and from the memory devices in a second unit size, a buffer and cache can be used to limit the written data to those portions of the second unit size which have been changed. Each of these devices reduces the total access time for writing to arrayed recording devices.

Recording apparatus and method for an arrayed recording apparatus

A semiconductor storage system comprises a semiconductor storage element array including a plurality of semiconductor memory elements, a data bus for transferring data to said semiconductor storage element array, an address bus for inputting an address to said semiconductor storage element array, a read/write controller for controlling read/write of the data written to said semiconductor storage element array, an interface control module for controlling a transfer/receipt of data and commands to and from an outside system, a microprocessor for controlling said read/write controller and said interface control module, a defect address memory for storing and outputting information on an address where at least one defective bit exists and an alternate address to be substituted for said address, and a defect address manipulating circuit for substituting said alternate address for said address where said defective bit exists in accordance with an output of said defect address memory.

Semiconductor storage system including defective bit replacement

A recording device includes a first unit operable in response to head positioning information to generate a first positioning signal for positioning a head at a predetermined track and a second unit operable in response to the first positioning signal to generate a second positioning signal for positioning the head at either a track between adjacent predetermined tracks or a position correction information area which is offset from the data area, thereby providing a high density and high precision recording device.

Method and apparatus for processing positioning signals in a record

A disk unit including a control unit for controlling the stop position of a positioning electric motor and positioning a magnetic head operatively linked with the positioning electric motor on a predetermined one of data tracks on a magnetic disk, and positioning error adjustment unit for supplying analog signals to the control unit, wherein the analog signals are related to the positioning error detected by the magnetic head. The control unit includes a control circuit for causing an exciting current which goes high during a time interval T1 and goes low during a time interval T2 during a period T to flow in a first exciting coil of the motor and for causing exciting current which goes low during the same time interval T1 and goes high during the same time interval T2 to flow in another exciting coil adjacent to the first coil, as a function of the magnitude of the aforementioned analog signal; the duration of the time intervals T1 and T2 with respect to the period T is adjusted by the control unit.

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Tokyo, Japan

Masahiro Mizuno