| 摘要 |
A first data transfer module sends update data to be written into a primary volume to a second data transfer module; the second data transfer module stores the update data into a secondary volume, stores differential data written to a storage address for the update data in the secondary volume into a second differential volume, updates a second management information holding module, and then informs completion of the data updating to the first data transfer module; and the first data transfer module stores the update data to an update address in the primary volume when the information of completion of the data updating is received from the second data transfer module, stores the differential data into a first differential volume, and updates a first management information holding module. |
