Patent ID: 7313663

Claim:
A storage system group, comprising: a first storage system coupled to at least one first host computer and comprising a plurality of first disk drives, a first portion of said first disk drives being related to a first logical volume and a second portion of said first disk drives being related to a second logical volume; and a second storage system coupled to at least one second host computer and said first storage system and comprising a plurality of second disk drives, a first portion of said second disk drives being related to a third logical volume and a second portion of said second disk drives being related to a fourth logical volume, wherein said storage system group performs a first asynchronous remote copy process according to a first status in which: said first logical volume functions as a primary logical volume which stores data sent from said first host computer, said third logical volume functions as a journal storing logical volume in which stores journal corresponding to journal, corresponding to data sent from the first host computer to the first storage system, and said fourth logical volume functions as said auxiliary logical volume, which forms a pair relationship with said primary logical volume and stores data corresponding to journal stored in said third logical volume, wherein said storage system group performs a second asynchronous remote copy process according to a second status in which: said fourth logical volume functions as a substitute for said primary logical volume, said second logical volume functions as a substitute for said journal storing logical volume, and said first logical volume functions as a substitute for said auxiliary logical volume, wherein said storage system group is changed from said first status to said second status based on one or more commands, wherein said first host computer, said second host computer or another computer displaying said first logical volume, said second logical volume, said third logical volume and said fourth logical volume based on at least one request.