Patent ID: 6985994

Claim:
A storage control apparatus in a storage system comprising a first storage control apparatus for receiving a data input/output request from an information processing apparatus and performing a data input/output process relative to a first storage volume for storing data and a second storage control apparatus connected to said first storage control apparatus in a communication enable state for performing a data input/output process relative to a second storage volume for storing data, said first storage control apparatus comprises: a first memory for storing data transferred between said first storage control apparatus and said second storage control apparatus; a second memory; an input/output control unit for writing data transfer information in said second memory, said data transfer information containing a storage location of data in said first memory and a storage location of data in said second storage control apparatus; and a data transfer control unit having a data buffer for storing data and a data transfer register for storing said data transfer information, said data transfer control unit controlling data transfer between said first memory and said second storage control apparatus via said data buffer in accordance with said data transfer information read from said second memory and written in said data transfer register, wherein, when a second data transfer based on second data transfer information is controlled while a first data transfer based on first data transfer information is controlled, said data transfer control unit writes said first data transfer information stored in said data transfer register and data stored in said data buffer into said second memory, reads said second data transfer information from said second memory, writes said second data transfer information in said data transfer register, and in accordance with said second data transfer information, controls said second data transfer.