Patent ID: 7159088

Claim:
A storage system connected to another storage system storing received data, said storage system having a primary volume related to a first portion of at least one first disk drive, said another storage system having a secondary volume related to a first portion of at least one second disk drive, said primary volume and said secondary volume being in a pair relationship, comprising: a data set storage region, which is related to a second portion of said at least one first disk drive, for storing a data set containing data, which corresponds to an update data targeted to said primary volume, and update information for managing said data; and a control section for generating said data set containing said update information for managing the data, storing said generated data set in said data set storage region, and sending a data set in said data set storage region to said other storage system, wherein said data set storage region is divided into a plurality of storage regions including a first storage region and a second storage region; said data comprises first data and second data, said first data and said second data corresponding to a plurality of data sequentially received by said storage system; and said control section generates a first data set containing said first data and first update data that is update data for said first data; stores at least said first data of said generated first data set in said first storage region; generates a second data set containing said second data and second update data that is update data for said second data; and stores at least said second data of said generated second data set in said second storage region that is a different storage region from said first storage region; wherein said control section, based on new first data and new second data being different from said first data and said second data, respectively, repeats to generate a new first data set, to store at least said new first data of said generated new first data set in said first storage region, to generate a new second data set, and to store at least said new second data of said generated new second data set in said second storage region.