Hitachi, Ltd.

Hitachi Microcomputer System, Ltd.

Koji Ozawa

Katsunori Nakamura

Masamitsu Takahashi

Takao Satoh

Akira Yamamoto

Yoshihiro Asaka

Hiroyuki Kitajima

Shigeo Honma

Takeshi Koide

Michio Miyazaki

Kazuhide Sano

Toshiaki Tsuboi

Kazuhito Suishu

Takahisa Kimura

Kosaku Kambayashi

Hitoshi Shiozawa

Ryo Fujita

Kazuyoshi Koga

Masahiro Shiraishi

Kazuhisa Takami

Mitsuru Soga

Kazunori Oniki

Takaharu Morishige

Hiroshi Arakawa

Yusuke Hirakawa

Shinji Kimura

Soichi Takaya

Tomohiro Murata

Manabu Araoka

Masaharu Akatsu

Keisuke Yamane

Morihiko Yotsuya

Kenzou Kurihara

In a data processing system in which main and sub disk storage devices are under the control of individual each disk control devices, the write processing time is reduced by selectively sending data according to the command-chaining time between main and sub disk control devices. A section for judging cable length and function of the sub disk control deviceestimates command-chaining time between a pair of main and sub disk storage devices. The channel command analyzing sectionestimates the number of records to be transferred and the length of a record using a LOCATE RECORD command. The command judgment section for the sub disk control deviceoptimizes the command-chain to be issued to the sub disk control device using the above-mentioned information. Then, the section for issuing command to the sub disk control deviceissues the optimized command chain. Thus, a shorter transmission time is realized by either sending individual records or an entire track of data.

External storage control device and data transfer method between external storage control devices

The invention is a copy processing technique in a data processing system, which can simultaneously achieve long-distance communication and no data loss when disaster occurs. Among a production site, a local site, and a remote site, long-distance remote copying from a disk array device at the production site to a disk array device at the remote site without data loss is achieved via a disk array device at the local site in combination with synchronous remote copying and asynchronous remote copying. Also, in the disk array devices at the local site and the remote site, copying is performed through a replica function. Even if the production site is affected by disaster, tasks can be continued at the local site having the same data as that of the production site and at the remote site a long distance away from the production site.

Data processing system and copy processing method thereof

If the pair state of a certain volume pair in one copy group is a fault state which has changed due to occurrence of a fault in the volume pair, then a write holding state is set for the copy group, and after setting the write holding state, the pair states of all the other volume pairs belonging to the copy group are set to a copy halt state. When setting the write holding state, and when executing setting of the copy halt setting state, commands from an open host are not necessary.

Storage system with mainframe and open host performing remote copying by setting a copy group

The present invention provides a storage system and a method of controlling the storage system, in which a second site rapidly resumes system process when a first site is damaged. The storage system comprises a first site including a first storage device, a second site including a second storage device, and a third site including a third storage device, and the method of controlling the storage system comprises a step of making a logical volume of the second storage device consistent with a logical volume of the first storage device by remotely copying only the differential data between the logical volume of the first storage device and the logical volume of the second storage device from a logical volume of the third storage device to the logical volume of the second storage device when the first site is damaged.

Storage system, method of controlling storage system, and storage device

Disk units operable under control of different disk control units hold the same data. Under circumstances in which data is duplexed, when data is duplexed again after data that is generally saved as backup data was accessed for reading and writing, in order to efficiently duplex data, update places of both original data and sub-data updated during the duplexing of data is interrupted are registered on an access information management table of an original disk control unit. When the original disk control unit receives a duplexing resume command, the duplexing of data may be efficiently reorganized by copying original data corresponding to an access place produced during the duplexing is interrupted from information of the access information management table to the backup data or by copying the backup data to the original data.

Subsystem and method of organizing multiplexed data

A clustering storage system, which enables to operate a plurality of storage system units as a single storage system, presents connection information between clustering storage systems to a user and receives data to be backed up and an instruction about a path between the clustering storage systems from the user. The clustering storage system uses load information or a transfer speed of a data connection line between the storage system units to determine a path between the clustering storage systems used for backup and a storage system unit for holding a backup copy so that the data transfer between the storage system units becomes minimum. Besides, the clustering storage system mainly uses the determined path for backing up the data.

Clustering storage system

Subsystem and method of reorganizing multiplexed data

In a data processing system in which main and sub disk storage devices are under the control of individual each disk control devices, the write processing time is reduced by selectively sending data according to the command-chaining time between main and sub disk control devices. A section for judging cable length and function of the sub disk control device estimates command-chaining time between a pair of main and sub disk storage devices. The channel command analyzing section estimates the number of records to be transferred and the length of a record using a LOCATE RECORD command. The command judgment section for the sub disk control device optimizes the command-chain to be issued to the sub disk control device using the above-mentioned information. Then, the section for issuing command to the sub disk control device issues the optimized command chain. Thus, a shorter transmission time is realized by either sending individual records or an entire track of data.

In a data processing system in which main and sub disk storage devices are under the control of individual each disk control devices, the write processing time is reduced by selectively sending data according to the command-chaining time between main and sub disk control devices. A section for judging cable length and function of the sub disk control device,estimates command-chaining time between a pair of main and sub disk storage devices. The channel command analyzing section,estimates the number of records to be transferred and the length of a record using a LOCATE RECORD command. The command judgment section for the sub disk control device,optimizes the command-chain to be issued to the sub disk control device using the above-mentioned information. Then, the section for issuing command to the sub disk control device,issues the optimized command chain. Thus, a shorter transmission time is realized by either sending individual records or an entire track of data.

In allocating an area of a cache memory to each storage unit, proper allocation of the cache memory is made to each storage unit. If the amount of write-after data becomes equal to or more than a threshold value, an allocation limit is set to each disk unit. If CPU issues a data write request requiring the amount of data equal to or more than the allocation limit, the data write request is held in a wait state until the amount of write-after data becomes less than the allocation limit. Therefore, the allocation amount to the disk unit becomes neither too large nor too small. In this manner, proper allocation of the cache memory to each disk unit can be realized.

Controller limiting modification of cache based upon amount of dirty

In a data processing system in which main and sub disk storage devices are under the control of individual each disk control devices, the write processing time is reduced by selectively sending data according to the command-chaining time between main and sub disk control devices. A section for judging cable length and function of the sub disk control device 36 estimates command-chaining time between a pair of main and sub disk storage devices. The channel command analyzing section 31 estimates the number of records to be transferred and the length of a record using a LOCATE RECORD command. The command judgment section for the sub disk control device 32 optimizes the command-chain to be issued to the sub disk control device using the above-mentioned information. Then, the section for issuing command to the sub disk control device 35 issues the optimized command chain. Thus, a shorter transmission time is realized by either sending individual records or an entire track of data.

External storage control device and data transfer method between

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Ninomiya, Japan

Koji Ozawa