Hitachi, Ltd.

Mitsuhiko Oguchi

Hidehiko Iwasaki

Tsutomu Sukigara

Yuichi Otani

Takashi Takenaka

Iwao Matsuyama

Masayuki Katsumoto

Nobuyuki Ishii

Kazuhisa Murakami

Masaki Otsuka

Satomi Yamaguchi

Tsuneyuki Hasegawa

A method and system which prevents starting-up problems in plural magnetic disk storage devices included in a disk array system during restart following halt of the magnetic disk storage devices after long term operation. The disk array system includes the plural magnetic disk storage devices, a microprocessor unit (MPU) which controls the magnetic disk storage devices, a control memory, a parity calculator, and cache memory. The control memory contains a operation time control table in which a tolerable continuous operation time Ti and a halt time Ts are stored. Each of the magnetic disk storage devices is intentionally stopped individually for the halt time Ts at time interval of the tolerable continuous operation time Ti. A request for reading data from one magnetic disk storage device under halt is responded to by using a data recovery function, while a request for writing data to a magnetic disk storage device under halt is responded to by writing data to an alternate spare magnetic disk storage device or memory.

Magnetic disk storage device control method, disk array system control method and disk array system

Magnetic disk storage device control method, disk array system control

Gas contaminants generated from the grease of bearings operating in a magnetic disk device adhere to the magnetic head and causing stiction and magnetic head crash. Such bearings are typically spindle bearings and pivot bearings. In operation, heat is generated that causes the bearing grease to generate the gases. By heat treating the grease, slow evaporating substances of hydrocarbon compounds with carbons of C9 to C13 in the grease are reduced to not more than 0.001 wt. % of the grease. The grease can then be used to lubricate the bearings. The heat treatment is performed at a temperature of 60.degree. to 100.degree. C. at a pressure of 10.sup.-3 to 10.sup.-8 torr. The assembled, lubricated bearings can be heat treated separately from the magnetic disk device or the heat treatment can take place after the bearings have been assembled in the magnetic disk device.

Bearing and manufacturing method of bearing, and magnetic disk device

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Ebina, Japan

Mitsuhiko Oguchi