Fujitsu Corporation

Yasuyoshi Sugesawa

Takuya Kurihara

Takashi Murayama

Sawao Iwatani

Keiichi Yorimitsu

Tatsuhiko Machida

Hidetoshi Nishi

Satoshi Yazawa

Sanae Kamakura

Suijin Taketa

Yuuichi Tarouda

A disc array device for maintaining consistency of data. When write processing is interrupted and then restarted, new data may be stored in a nonvolatile memory and regeneration of parity may be impossible because data can not be read out normally from a disc device other than a disc device in which new data is to be written and a disk device for parity. In such a case, a special write executing unit overwrites the new data stored in the nonvolatile memory at a specified write position of the disk device in which new data is to be written.

Disk array device

Each semiconductor memory module is divided into a plurality of access control units, and a service adapter copies the contents of the memory of the semiconductor memory module in which a memory error has occurred, to a spare semiconductor memory module one access control unit at a time. It is thus possible to evacuate the contents of the memory of the semiconductor memory module in which the memory error has occurred without stopping the semiconductor disk apparatus simply by adding the spare semiconductor disk apparatus. Since the copying operation is executed one access control unit at a time, a resource manager can conduct exclusive control also one access control unit at a time. A host apparatus therefore can access an access control unit portion which is not the object of copying even in the process of copying. In other words, the copying operation exerts no deleterious influence on the access of the host apparatus.

Semiconductor disk apparatus having a semiconductor memory for a

Growing community of inventors

Kanagawa, Japan

Yasuyoshi Sugesawa