Patent ID: 8312235

Claim:
A data processing system comprising: a first storage system configured with a virtual logical volume that comprises a dynamically expandable volume; a second storage system coupled to the first storage system through a data copy network; a host computer configured to input data to the virtual logical volume; and a management server coupled to the host computer, configured to manage the virtual logical volume, wherein the first storage system comprises: a first pool configured from a plurality of physical disks and comprising a plurality of segments of a first storage region each with a respective capacity, wherein the first storage system is configured to assign one or more of the plurality of segments in the first pool as a current capacity to the virtual logical volume, in response to a request from the host computer to input data, wherein the second storage system comprises: a second pool configured from a plurality of physical disks and comprising a plurality of segments of a second storage region each with a respective capacity, wherein the management server is configured to perform a migration of data comprising: (A) confirming a connection status of the host computer and the virtual logical volume upon receiving a request from the host computer for migrating data corresponding to at least a part of the virtual logical volume, from the first storage region to the second storage region; (B) transmitting to the first storage system, as a reservation capacity, when the host computer and the virtual logical volume are coupled, a maximum capacity of the data held in the one or more segments of the first storage region requested by the host computer to be assigned to the virtual logical volume for the migration, and transmitting to the first storage system, as the reservation capacity, if the host computer and the virtual logical volume are not coupled, the current capacity of the one or more segments of the first storage region which are currently assigned to the virtual logical volume, wherein the first storage system is configured to reserve the second storage region, with a capacity based at least in part on the reservation capacity transmitted from the management server, and wherein the first storage system is configured to execute a migrating of at least a portion of the data corresponding to the virtual logical volume from the first storage region to the second storage region, after the reservation of the second storage region.