Hitachi, Ltd.

Bunitsu Ando

Ikuya Yagisawa

Yoshihiro Oikawa

Koji Iwamitsu

Shinjiro Shiraki

Hidekazu Aoyama

A controller transmits a second protocol command to a target from among one or more switch devices. The second protocol command is a command which conforms to a second protocol type in which a connection established for transmitting a command to the target is broken during processing of the command by the target, and is defined as a command corresponding to a first protocol command, which is a command conforming to a first protocol type in which the connection remains established during processing of the command by the target.

Data storage system using multiple communication protocols

Data storage using multiple protocols

A storage control apparatus of the present invention controls the number of multiple commands issued from a host machine without shutting down the host machine. A communication port of the storage control apparatus carries out communications with the hosts in accordance with the iSCSI protocol. Command processing resources are managed for each communication port. A resource allocation control part calculates the number of commands capable of being received on the basis of the remaining amount of command processing resources inside shared port resources, a change in the number of commands received from a host, communication delay time, and the state of execution of a command issued from a host or the like. A MaxCmdSN is calculated by adding the results of command processing by a command execution part and the receivable number calculated by the resource allocation control part to the value of the latest CmdSN received from a host. The storage control apparatus adds the MaxCmdSN to a transmission frame and transmits it to the host.

Storage control apparatus and method for controlling number of commands executed in storage control apparatus

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Hiratsuka, Japan

Bunitsu Ando