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.