Patent ID: 8407436

Claim:
A thin provisioning storage system comprising: a plurality of data storage units, the plurality of data storage units being divided into a plurality of chunks forming a chunk pool; at least one network interface configured to connect the storage system with a source thin provisioning storage system and at least one host computer; and a storage controller controlling the plurality of data storage units to store data via a cache, comprising a central processing unit, the cache, and a memory, the storage controller configured to: import source mapping information and source pool information from the source thin provisioning storage system, the source mapping information being indicative of a correspondence of allocated chunks to a source data storage volume in the source thin provisioning storage system, the source pool information being indicative of allocation of chunks from a source chunk pool of the source thin provisioning storage system; use the source mapping information and the source pool information to provision a target data storage volume and to update a mapping information and a pool information stored in the memory; make the provisioned target data storage volume available to the at least one host computer via the at least one network interface, wherein the source thin provisioning storage system and the thin provisioning storage system are connected to each other by the at least one network interface, and wherein the import of the source mapping information and the source pool information is conducted through the at least one network interface, and wherein the storage controller includes information on whether data is located internally or externally; wherein upon receiving a write access, the storage controller updates the mapping information according to an allocation of the write access; and wherein the storage controller is further configured to: relocate data in the source data storage volume of the source thin provisioning storage system to the provisioned target data storage volume; update the mapping information to reflect the relocation of the data, wherein the relocation is performed according to access rate against each chunk; unify at least one internal chunk pool and at least one external chunk pool based on the import of the source mapping information and the source pool information, and to allocate one of the at least one internal chunk pool to data associated with a first access rate and to allocate one of the at least one external chunk pool to data associated with a second access rate, where the first access rate is larger than the second access rate; and wherein the source thin provisioning storage system includes a storage controller for creating the source mapping information and the source pool information.