Hitachi, Ltd.

Toyohiko Kagimasa

Yoshimasa Masuoka

Fumio Noda

Yoshifumi Takamoto

Hitoshi Kakuta

Shigekazu Inohara

Kikuo Takahashi

Toshiaki Mori

Jinghua Min

Seiichi Yoshizumi

Katsuyoshi Kitai

Shizuo Gotou

Yoshiki Matsuda

Atsushi Tanaka

Hiroki Kanai

Yoshihisa Kamo

Satoshi Yoshizawa

Masaaki Shimizu

Yooichi Shintani

Toshiyuki Ukai

Osamu Chinone

Akihiko Ohba

Shigeo Yonenaga

Kikuo Takahasi

Tohiyuki Ukai

Mitsuo Ohyama

Yoshie Ono

In order to perform format conversion between the formats of a plurality of files without any work by a user, a file system stores a relation between a conversion originating file and a conversion destination file, and synchronously with an issue of a file operation API, the format conversion processes are executed. A user performs only the tasks essential for an application, without taking into consideration various necessary format conversions (either one-step or multi-step). During the user task, it is not necessary to designate a conversion originating file and a timing of format conversion. A user can use always a latest conversion destination file.

File format conversion method, and file system, information processing system, electronic commerce system using the method

Irregular and unstable natures of the Internet to be caused by an increase in Internet accessing users are alleviated and services of an information system more comfortable to users are provided. To this end, each servers among a plurality of servers cooperating to provide services stores the past communications line state (throughput and latency), and in accordance with the stored communications lines state, cache reference and prefetch are preformed between optional servers.

Method and system for managing distributed data

In correspondence to an application, a resource table to manage computing resources which are available for the application is provided in a rule such that a plurality of applications can mutually use distributed computing resources which could be used so far by itself and can effectively use many distributed computing resources and an execution performance can be raised. When a certain application executes a cooperative processing together with another application, resource tables are copied and a new resource table for managing resources of both of them is formed. By referring to a newly formed resource table by each application, each application can use both of the computing resources more efficiently.

System using environment manager with resource table in each computer

A networking method and system for performing data communication to a client computer from a server computer having a plurality of network interfaces through a network. The invention includes a LAN switch, provided between the network and the server computer. The LAN switch includes a plurality of communication paths correspondingly connected to the network interfaces of the server computer. Any one of the communication paths are usable to connect the client computer with the server computer. The invention further includes a selector for selecting one of the communication paths in accordance with a quality of service (QOS) requested by the client computer. The selector selects the communication path using information contained in a routing table in the server computer based on a network address of the network connected to the client computer. The routing table includes the address of the network connected to the client computer and addresses of network interfaces of the server computer correspondingly connected to the communication path.

Networking system and parallel networking method

A computer system, which is intended for easy introduction of architectures and fundamental softwares used by users, includes one or more first computers which implement the user interface function, one or more second computers which run application programs, and a third computer which administrates the first and second computers. A first computer turned on by a user operates on the third computer to assign a second computer for running a fundamental software which controls the execution of a user's application program. The assignment of a computer which runs the fundamental software for the user's application program at the time of user request facilitates the introduction, administration and operation of fundamental softwares and computers.

Shared computer system for selective execution of fundamental software

Logical blocks are allocated to a plurality of logically sequential blocks of data by referring to disc array configuration information and a list of candidate logical blocks that may be allocated, so that the drives for retaining the logical blocks assigned to the blocks of data and the drives for holding the parities for these logical blocks will be all different. Thus, a total number of drives which operate in parallel for executing sequential writes to the disc array can be increased to a maximum extent.

Allocation method of physical regions of a disc array to a plurality of

A plurality of disc units, an array control unit, and a host controller connecting mechanism for connecting them to a host controller through a system interface are mounted on the same circuit board. The order of interrupts of requests for connecting of disc units is detected, and the disc units are connected to a common bus selectively. Cables for interconnecting constituent elements of the disc array device and supporting mechanisms for the disc units can be dispensed with, and consequently the cost can be reduced. Useless rotation waiting is avoided, improving the data transfer rate. The disc array device can be built in the host device and connected directly to the system bus. Therefore the ease of operation can be improved.

Disc array device and disc control method

A disc array system has a plurality of disc storage devices (i.e., drives) constituting a parity group and mounted in a distributed manner on different boards. Where any one drive in the same parity group develops a fault, the board carrying the faulty drive is withdrawn from the mother board for repair. If the CPU issues a write request for data held in the faulty drive or in any normal data on the same board, the requested data is recovered from the multiple data retained in the other drives constituting the same logical group and mounted on the other boards. The recovered data is sent to the CPU. If the CPU supplies write data to the faulty drive or to any normal drive on the same board, the supplied write data is held temporarily in a cache memory in an array controller. Later, when the board is repaired and replaced onto the mother board, the data to be held in the alternate drive having replaced the faulty drive is recovered from the data in the other drives, and the recovered data is written to that alternate drive. Then the write data in the cache memory is written to the alternate drive or to the target normal drive.

Disc array system having disc storage devices dispersed on plural boards

To transfer a file comprising block data at high speed between sequential access type auxiliary memories, a file transmission program inquires of an operating system about the physical storage positions of the block data, determines a reading order to reduce the read access time on the basis of the results of inquiry, and issues read requests sequentially to the operating system according to the reading order. The file transmission program requests the operating system to transmit the read block data. The block data together with respective logical identification data, for example, logical block numbers, are transmitted to a receiving end which may be another computing system. The operating system at the receiving end is requested to secure the number of physical data blocks required to store the block data. The write order of the block data to the physical data blocks is then determined to reduce the access time and the block data are respectively stored in the secured physical data blocks according to the write order. Sequentially, a pair of the logical identifiers of each block data actually written to the data area and physical identification data of the data blocks are stored in the data area.

Process of transferring file, process of gaining access to data and

A drive unit connected to a disk control unit of a disk array has a logical group formed of a plurality of drives. In the logical group, both original data and duplexed data of the original data are stored. The original data and the duplexed data thereof are stored in different drives. When a plurality of data stored in one drive are to be read, the original data or the duplexed data thereof are read in parallel from the different drives.

Disk array with original data stored in one disk drive and duplexed data

In a data processing system to which a large number of disk drive units are connected, data in the whole or part area of a file are multiplexed and distributed into a plurality of disk drive units when the file is opened, and the multiplex data of the file are deleted when the file is closed. Among the multiplex data, data shortest in access time or striped data shortest in transfer time is selected to be accessed. When data multiplexing is applied only to the part area, the data storage capacity of the system can be reduced more remarkably.

File data multiplexing method and data processing system

A method for allocating real pages larger than a conventional size to a plurality of virtual pages of the conventional size in a system including a real storage containing a plurality of real pages and a storage key for holding storage keys used for storage protection purposes of the real pages. The method includes the steps of (A) allocating one of plural split regions having the conventional size obtained by subdividing one of a plurality of real pages having a larger size equal to a value n being a positive integer larger than 1) times larger than the conventional size, to one virtual page having the conventional size (B) repeating step (A) so that split regions having the conventional size within the one real page and within other real pages having the larger size are allocated to virtual pages having the conventional size. Either a real page of a larger size or a group of consecutively located split regions of the convention size are allocated to a virtual page of a size larger than the conventional size.

Growing community of inventors

Sagamihara, Japan

Toyohiko Kagimasa