Patent ID: 8190815
Filing Date: 2012-05-29
Classification: G06F

Abstract:
1. A storage system, comprising: a first storage subsystem connecting to a first upper system; a second storage subsystem connecting to a second upper system; storage devices to which the first storage subsystem and the second storage subsystem are connected respectively; and a connection bus which enables the exchange of data or commands by connecting the first storage subsystem to the second storage subsystem; and wherein the storage devices include a first type of storage device and a second type of storage device, wherein the first storage subsystem includes: a first hard disk drive including a plurality of segments for storing data, a first flash memory drive including a plurality of sectors for storing data, and a first controller including: a first cache memory that is coupled to the first hard disk drive and the first flash memory drive and that temporarily stores write data to be written in the first hard disk drive, read data from the first hard disk drive and read data from the first flash memory drive, a second cache memory that is coupled to the first flash memory drive and that temporarily stores write data to be written in the first flash memory drive without storing write data to the hard disk drive, wherein the first controller transfers the write data in the second cache memory to a sector of the first flash memory drive in a sector unit, wherein data in the sector of the first flash memory drive is erased before storing the write data transferred from the first controller, and wherein the first controller transfers the write data in the first cache memory to a segment of the first hard disk drive without erasing data in the segment, and wherein the second storage subsystem includes: a second hard disk drive including a plurality of segments for storing data, a second flash memory drive including a plurality of sectors for storing data, and a second controller including: a third cache memory that is coupled to the second hard disk drive and the second flash memory drive and that temporarily stores write data to be written in the second hard disk drive, read data from the second hard disk drive and read data from the second flash memory drive, a fourth cache memory that is coupled to the second flash memory drive and that temporarily stores write data to be written in the second flash memory drive without storing write data to the hard disk drive, wherein the second controller transfers the write data in the fourth cache memory to a sector of the second flash memory drive in a sector unit, wherein data in the sector of the second flash memory drive is erased before storing the write data transferred from the second controller, and wherein the second controller transfers the write data in the third cache memory to a segment of the second hard disk drive without erasing data in the segment.