Storage control apparatus and method

A storage control apparatus and a storage control method are provided wherein in a system having a plurality of disk systems (200) and secondary disk systems (300) at remote sites, the data transfer amount between a central processing unit (100, 400) and a disk system (200, 300) can be reduced when duplicate disk write is performed, the performance can be prevented from being degraded even if the distance between control units is elongated, and the intermediate results of a transaction are not left. A standard time is determined and a program is provided which instructs a secondary central processing unit to reflect only update information having a write time older than the standard time, upon a logical disk in the secondary disk system.