Patent ID: 7424583

Claim:
A storage system comprising: a first disk array apparatus for providing first volumes for storing data sent from a host system; a second disk array apparatus for providing second volumes for storing back-up data of the first volumes; and a console terminal for operating the first disk array apparatus, wherein the console terminal includes a setting unit for setting a priority for each first volume in accordance with an external command, wherein the first disk array apparatus includes: a storage unit for storing the priorities set by the priority setting unit; and a transfer unit for reading the priorities from the storage unit upon receiving the data, and transferring the data stored in the first volumes to the second volumes of the second disk array apparatus in order of descending priority of the first volumes that store the data, and wherein the first disk array apparatus includes: a counting unit for counting the number of times data is received for each first volume; and a priority increase/decrease unit for increasing or decreasing the priority stored in the storage unit based on the data-reception count counted by the counting unit.