US Patent 7269690 Disk array device and data processing method thereof

A data processing method for a disk array device capable of achieving a duplex system of data and improving performance of the same device while a quantity of processing for writing into a cache memory (through a switch) is reduced. In the disk array device, a host interface portion comprises a nonvolatile memory portion for saving data written from a host computer/server, and a data transfer control portion for transferring write data from the host computer/server to the nonvolatile memory portion and a global cache memory portion. If a write request is received from the host computer/server, a data transfer control portion transfers the write data from the host computer/server to the nonvolatile memory portion and to the global cache memory portion through a switch portion.