Patent ID: 7185227

Claim:
An information processing system comprising: a computer; and a storage system, coupled to the computer, which receives a write request from the computer; wherein the storage system further comprises: a control unit processing the write request from the computer; a first storage, coupled to the control unit, which stores data related to the write request targeted to the first storage from the computer; a second storage, coupled to the control unit, which stores a copy of data of the first storage at a first point in time; and a third storage, coupled to the control unit, which records, write data related to the write request targeted to the first storage from the computer with time information and/or sequence numbers, and a plurality of checkpoints in time for recovery received from the computer, as journal data of the first storage, wherein the checkpoints uniquely identify a system state in the computer and the storage system; wherein when the control unit receives a restoration request including a desired checkpoint information specifying one of the plurality of checkpoints, the information processing system generates an image of the first storage at a desired point in time specified with the desired checkpoint information based upon the copied data stored in the second storage, and journal data which are stored in the third storage and which are specified by the desired checkpoint and the first point in time.