The present invention relates to storage apparatuses for performing asynchronous remote copying between primary and secondary disk controllers. In particular, the present invention relates to techniques effective for adaptation to the transfer of update data.
Conventionally, when performing an asynchronous remote copying between a primary disk controller of a storage apparatus and a secondary disk controller thereof, by way of update data from the primary disk controller to the secondary disk controller, all write data to the primary disk controller are transferred.
Japanese Unexamined Patent Application Publication No. 2003-202962 discloses a storage controller proposed to achieve an object of minimizing performance deterioration even at an increased inter-controller distance. To achieve the object, after a termination notification of write data is returned from a primary disk controller, the write data is directly transmitted to a secondary disk controller, and the secondary disk controller stores the received data into a nonvolatile memory, whereby data securement is performed. In addition, predetermined reference time is set to enable all write data occurring before the reference time to be secured and to enable all data occurring after the time to be abandoned.