Disclosed herein is a method for controlling a storage device controller
connected to a storage device provided with a plurality of storage
volumes for storing data respectively and an information processing
apparatus for requesting an input/output of data so as to receive an
input/output request from the information processing apparatus and
execute an input/output processing of the data for each of the plurality
of storage volumes. The method brings one (primary) of the plurality of
storage volumes into correspondence with another (secondary) in which a
copy of data is to be written when the data is written in the primary
volume so as to form a pair group consisting of a plurality of pairs,
each having such a primary volume and such a secondary volume.