Fujitsu Corporation

Takeshi Obata

Masahiro Yoshida

Sawao Iwatani

Suijin Takeda

Mitsuhiko Yashiro

Taichi Oono

Taichi Ohno

A log management moduleacquires log data from a computer, temporarily stores the log data in a buffer, and writes the stored log data into a disk device. When the log management moduledetects a failure in the computer, the log management modulestops writing log data in the disk device, and writes log data acquired after the failure is detected in a disk device

Method, apparatus, and computer product for managing log data

A storage system have a plurality of control modules which control a plurality of disk storage devices, in which system information reading/writing is possible even when problems arise in paths with a plurality of disk devices, and moreover log data can be output even upon occurrence of an abnormality in a control module. A plurality of control modules has built-in a pair of system disk device units which store log data. Upon occurrence of an abnormality in one control module, a system disk unit of one control module is removed and mounted in another control module, and the log data of the mounted system disk unit is output by the another control module.

Data storage system and log data output method upon abnormality of storage control apparatus

A storage system have a plurality of control modules which control a plurality of disk storage devices. In order to read/write system information even when problems arise in paths with the plurality of disk devices, and moreover to output log data even upon occurrence of an abnormality in the control module, a plurality of control modules which control a plurality of disk storage devices, each have a built-in system disk device unit which stores log data. In equalization processing, log data of one control module is stored in a system disk of another installed control module. Even when an abnormality occurs in the one control module, log data of the one control module can be output by the other control module.

Data storage system and log data equalization control method for storage control apparatus

A parity which is used to a disk array is formed by using a cache memory. A storing method of the cache memory is classified into three methods such that: only data is stored; only redundant information is stored; and both of the data and the redundant information are stored. Even when a power source is shut off during the data writing process, the processing stages of the data writing and parity updating and the necessary data are stored into a non-volatile memory and are used for recovery.

Disk array apparatus that only calculates new parity after a

A parity which is used to a disk array is formed by using a cache memory. A storing method of the cache memory is classified into three methods such that: only data is stored; only redundant information is stored; and both of the data and the redundant information are stored. In order to save processing time, a new set of redundant information (or parity data) is not calculated for every data update. Instead, the new parity data is only calculated after there have been a predetermined number of data updates. In addition, even when a power source is shut off during the data writing process, the processing stages of the data writing and parity updating and the necessary data are stored into a non-volatile memory and are used for recovery.

Growing community of inventors

Kawasaki, Japan

Takeshi Obata