Patent ID: 7209986

Claim:
A control method in a virtualization system having a virtual storage volume and coupled to a host computer and a first disk array system, said first disk array system having a plurality of disk drives and a first logical volume related to said disk drives, said control method comprising: sending a first information request to said first disk array system for identifying a first Logical Unit Number (LUN) regarding said first logical volume, so that a relation of a first information regarding said first logical volume and a second information regarding said virtual storage volume is created, said first information including both a first World Wide Name (WWN) and said first LUN regarding said first logical volume, said second information including both a second WWN and a second LUN regarding said virtual storage volume; identifying said first LUN based on a response, received from said first disk array system, and corresponding to said first information request; storing said relation; receiving a data input/output request including said second LUN, sent from said host computer, and targeted to said virtual storage volume; changing at least said second LUN included in said data input/output request to at least said first LUN based on said relation; transferring said changed data input/output request to said first disk array system so that said first disk array system performs inputting/outputting of data corresponding to said changed data input/output request to/from said disk drives corresponding to said first logical volume.