Patent ID: 7424585

Claim:
A system for storing data comprising: a plurality of storage systems each including a storage controller and a logical volume provided by a plurality of disk devices coupled to the storage controller; and a virtualization controller coupled to the plurality of storage systems, wherein the virtualization controller includes: a virtualization section managing a plurality of virtual volumes, which are access targets of a host computer, provided by a plurality of logical volumes of the plurality of storage systems, and managing a relation between identifiers used by the host computer to access the plurality of virtual volumes to read/write data and information for accessing the plurality of logical volumes corresponding to the plurality of virtual volumes, wherein one or more virtual volumes are provided by one logical volume; and a management section managing a storage class relation between the plurality of virtual volumes and a plurality of storage classes defined on the basis of attributes of the plurality of logical volumes of the plurality of storage systems associated with the plurality of virtual volumes, wherein the management section receives information for specifying a source virtual volume and a destination storage class selected from the plurality of storage classes, the source virtual volume being accessed to read/write data by the host computer by using a first identifier; wherein a target virtual volume is selected from virtual volumes related to the destination storage class, wherein data of a source logical volume corresponding to the source virtual volume are migrated to a target logical volume corresponding to the target virtual volume, and wherein the first identifier used by the host computer to access the source virtual volume to read/write data is assigned to the target virtual volume instead of the source virtual volume by the virtualization section.