| 摘要 |
PROBLEM TO BE SOLVED: To enable quick reversion from a state in which sequential order is not guaranteed in a remote copy to a state in which sequential order is guaranteed.SOLUTION: If a capacity of a buffer 2c is short in a state where the buffer 2c stores first generation data 8b, second generation data 8c, and third generation data 8d, a control unit 2b specifies the first generation data 8b as specific data. The control unit 2b generates update record information 7 on the basis of the first generation data 8b and stores it in a storage unit 2a. The control unit 2b identifies a position where the first generation data 8b is stored in a copy source volume 3a according to correspondence relation information 6, and updates the copy source volume 3a using the first generation data 8b. The control unit 2b deletes the first generation data 8b from the buffer 2c, and deletes the correspondence relation information 6 corresponding to the first generation data 8b from the storage unit 2a.SELECTED DRAWING: Figure 1 |
