Patent ID: 7992035
Filing Date: 2011-08-02
Classification: G06F

Abstract:
1. A disk selection method for use with a plurality of disk devices having a mirroring configuration, the method comprising: determining whether there is a read request from a host computer during a rebuild process in which data is copied from a normal disk device which stores same data as data stored in a faulty disk device to a rebuild destination disk device, a first rebuilt area in the normal disk device and a second rebuilt area in the rebuild destination disk device being divided into a plurality of areas each includes a certain number of blocks smaller than a number of blocks of an area that the normal disk device and the rebuild destination disk device are read out during a normal read performed when the rebuild process is not performed, one of the plurality of areas in the normal disk device and one of the plurality of areas in the rebuild destination disk device being alternately assigned as an area from which data is read when there is the read request from the host computer during the rebuild process; and when there is the read request from the host computer during the rebuild process, selecting one of the plurality of areas in the normal disk device or one of the plurality of areas in the rebuild destination disk device for reading data in units of the certain number of blocks.