A data processing system has a plurality of storage systems. In this
system, data replication is performed at high speed and efficiency while
maintaining data integrity. In addition, when failure has occurred in a
configuration element, the time necessary to resume the data replication
is reduced. In accordance with an instruction from first host computer,
updating of replication-target data and creation of a journal are
performed in a storage system A; and updating of replication data and
creation of a journal are performed in a storage system B. A storage
system C retrieves a journal from the storage system B in
asynchronization with the updating, and performs updating of replication
data. When failure has occurred in the storage system B, a
journal-retrieving end is altered to the storage system, and the
replication data is updated in accordance with the retrieved journal.