Storage subsystem and performance tuning method

#The present invention relates to a technique of performance tuning of the whole storage subsystem having storage subsystems that are not directly connected to host computers.

#As a result of the recent spread of Internet and adaptation to development of broadband, an amount of information treated by a computer system increases year by year, and importance of information continues to increase. Accordingly, in a computer system, it is requested more and more strongly that a storage used for accumulating information read and written by a host computer (particularly a storage subsystem connected outside the host computer) should have high reliability, for example, in protection of the stored data, in addition to large capacity and high performance.

#A disk array system is one method of satisfying these requests together, in a storage subsystem.

#FIG. 1 is a block diagram showing an entire computer system of a first embodiment of the present invention;

#FIG. 2 is a diagram for explaining a functional configuration and a connection state of a storage subsystem and an external storage subsystem of the first embodiment;

#FIG. 3 is a diagram for explaining functions of a storage subsystem control unit 112 of the first embodiment;

#Now, embodiments of the present invention will be described referring to the drawings, although these embodiments do not limit the present invention.

#[Entire Configuration]

#FIG. 1 is a diagram for explaining an example of a configuration of a computer system according to a first embodiment of the present invention.