Various types of resources of the disk array device are divided for respective users and communications resources used in remote copying are appropriately assigned to the users so that functional interference between the split units is prevented and stable remote copying is realized. SLPRs which are dedicated regions for the respective users are set inside the disk array device 10. Each SLPR is constituted by dividing various types of resources of ports, cache memories, logical units and the like, and cannot be accessed by an unauthorized host computer 1. Furthermore, a manager of one of the SLPRs likewise cannot refer to or alter the constructions of the other SLPRs. During remote copying, the amount of transfer within the unit time is detected for each of the SLPRs. If the amount of transfer within the unit time exceeds the maximum amount of transfer, a response to the host computer 1 from this SLPR is deliberately delayed, so that the inflow of data from the host computer 1 is restricted.