Patent ID: 7447121

Claim:
A storage system, comprising: a controller adapted to be coupled to at least one of information processing devices and storing a plurality of data and a parity data in a plurality of storage regions, said parity data generated by using said plurality of data; a plurality of disk drives having said storage regions and having a plurality of first type disk drives each of which has a first type interface and a plurality of second type disk drives each of which has a second type interface; wherein said first type disk drives configure a first RAID (Redundant Array of Inexpensive Disks) group in which a plurality of first data and a first parity data are stored, wherein said second type disk drives configure a second RAID group in which a plurality of second data and a second parity data are stored, said second RAID group having a same redundancy of said first RAID group, and wherein said controller reads data from one or more said disk drives with a different procedure based on a type of disk drives from which data are read, if said controller receives a read request from said information processing device.