Fujitsu Corporation

Masatoshi Nakamura

Yoshihito Konta

Marie Abe

Koutarou Nimura

Atsushi Igashira

Hidefumi Kobayashi

Mihoko Tojo

Hideo Takahashi

Yasuhiro Ogasawara

Shigeru Akiyama

Tsunemichi Harada

Tomo Fukui

A control apparatus served as a first control apparatus includes a first information storage unit configured to store therein coupling information relating to a coupling relationship between a plurality of control apparatus and a plurality of devices, the plurality of control apparatus including the first control apparatus and controlling access to the plurality of devices, and a processor. The processor specifies, in response to a first access request to a first device from among the plurality of devices, a second control apparatus responsible for the first device based on the coupling information stored in the first information storage unit, and issues an instruction to access to the first device based on the first access request received by the first control apparatus to the specified second control apparatus through a relay apparatus that relays information to be transferred between the plurality of control apparatus.

Control apparatus, storage apparatus and computer-readable recording medium having stored therein control program

A receiver unit receives data write commands for a memory device. A control unit determines a use situation of an RMW cache used in a read-modify-write process by the memory device, on the basis of write sizes, a reception frequency, and the number of received commands. A control unit decides whether or not to execute a read-modify-write process by a storage control apparatus on the basis of the determination result.

Cache read-modify-write process control based on monitored criteria

A control device including a processor. The processor configured to allocate a data area of a memory device to a plurality of memory areas of data blocks of a first size; allocate identical data blocks of the first size to a plurality of the data areas of the memory device; manage management information indicating a data storing state of the plurality of memory areas of data blocks of the first size in each data area; determine, based on the management information regarding a plurality of data areas allocated with respect to a data block to be written, one data area from the plurality of data areas; and generate write data of a second size, which is different from the first size, including data of the data block to be written and write the write data in the one data area.

Control device, storage device, and computer-readable recording medium having stored therein control program

Write commands for a storage device specify write data with either a first data step size or a second data step size. In the former case, the storage device performs a read-modify-write (RMW) cycle which includes reading data with the second data step size. In the latter case, the storage device executes the command in a single write cycle. A command sorting unit sorts received commands into two groups, first commands and second commands, when storing them in a memory. First commands are write commands whose data boundaries do not match with the second data step size. Second commands include write commands whose data boundaries match with the second data step size. A command issuing unit converts first commands into a second command upon predetermined conditions. The command issuing unit issues the second commands to the storage device, in preference to the first commands.

Apparatus and method for reducing read-modify-write cycles by combining unaligned write commands

A storage device which includes a plurality of magnetic disk drives has a storage unit that stores, for each of the plurality of magnetic disk drives, information of whether or not the magnetic disk drive is incorporated in a redundant structure, a specifying unit that specifies, among the plurality of magnetic disk drives, a plurality of magnetic disk drives which have a redundant structure on the basis of the information stored in the storage unit, and a control unit that controls, for the plurality of magnetic disk drives specified by the specifying unit, an execution timing of sweep operation in which a head smoothes a lubricant material such that the sweep operation is executed for a single magnetic disk drive at a time.

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Machida, Japan

Masatoshi Nakamura