Patent ID: 7464232

Claim:
A data processing system having a storage system for providing a plurality of dynamically expansible volumes, each volume capacity set to be extended by assigning a part of a shared storage region, a host computer for inputting and outputting data to and from a volume of the plurality of dynamically expansible volumes, and a management server for managing said volume; wherein said management server comprises: a confirmation unit for confirming a connection status of said host computer and said volume upon migrating data stored in said part of said shared storage region assigned to said volume to another shared storage region; and a transmission unit for transmitting to said storage system a maximum capacity of said volume preset as requested by said host computer, when said host computer and said volume are connected as confirmed by said confirmation unit, and for transmitting to said storage system a current capacity of said volume, when said host computer and said volume are not connected as confirmed by said confirmation unit, wherein said storage system comprises a reservation unit for reserving said maximum or current capacity transmitted from said management server and exclusively securing said maximum or current capacity in said another shared storage region to which said data is to be migrated.