| 主权项 |
1. In a plurality of disk array units connected to one another through a network, the plurality of disk array units being each assigned to one of a plurality of nodes, a disk array unit comprising:
a psical switch which decides whether a node concerned is a basic node or an extended node; a control unit which, when the node concerned is said basic node, executes power source control of said extended node based on power source control information set at said basic node by inter-node communication executed through a common signal line which connects each said node; and a power source switch connected to the control unit and controls the control unit to execute power source control, wherein only an operation of the power source switch mounted on said basic node is determined as valid power source control information and an operation of the power source switch mounted on said extended node is determined as invalid power source control information, and wherein said control unit, when the node concerned is said basic node and power-off operation is input by the power source switch, issues a power-off request to a main body of said disk array unit, recognizes completion of saving of data of a cache memory in the main body of said disk array unit to transmit a power-off allowance notification to said extended node through inter-node communication, and executes power-off processing of a device power source of said basic node after obtaining a reception response of the power-off allowance notification transmitted from said extended node which has received the power-off allowance notification and has executed power-off processing of a device power source of said extended node. |
