Patent ID: 8161257

Claim:
A remote copy system for copying write data, which is sent from a host system to a first storage system configuring a local site, from said first storage system to a second storage system configuring a remote site, wherein said first storage system comprises: a primary data volume to which said write data is written; a first controller for creating journal data from said write data; a primary journal volume for storing the created journal data; and a second controller for transferring the journal data stored in said primary journal volume to said second storage system; wherein said second storage system comprises: a secondary journal volume for storing the journal data transferred from said first storage system; a secondary data volume corresponding to said primary data volume, wherein said journal data is restored from said secondary journal volume to said secondary data volume; a replica volume corresponding to said secondary data volume, wherein a copy pair is defined between said replica volume and said secondary data volume; and a third controller; wherein said journal data is given a time stamp; and wherein said third controller: (a) suspends restoration of said journal data from said secondary journal volume to said secondary data volume; (b) resumes restoration of said journal data from said secondary journal volume to said secondary data volume in response to a backup command, designating a time in the past, sent from said host system; (c) stops restoration of said journal data from said secondary journal volume to said secondary data volume when the restoration of said journal data having a time stamp up to said designated time in the past is complete; and (d) re-synchronizes said secondary data volume synchronized with said replica volume and splits said copy pair between said secondary data volume and said replica volume.