Patent ID: 7305584

Claim:
An information processing system comprising: a computer; and a storage system, which is coupled to the computer and which receives a write request from the computer; wherein the storage system further comprising: a control unit processing the write request from the computer; a first storage 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 particular 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, as journal data of the first storage, wherein the checkpoints identify a system state at detections of certain types of transactions; 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 particular point in time.