Patent ID: 7925831

Claim:
A disk array system connected to an information processing apparatus so as to be able to communicate with the information processing apparatus, the disk array system comprising: a first plurality of disk drives; a second plurality of disk drives; a third plurality of disk drives; and a disk control apparatus managing a first logical volume on the first plurality of disk drives, a second logical volume on the second plurality of disk drives and a third logical volume on the third plurality of disk drives, the first logical volume managed as a primary volume and configuring a copy pair with the second logical volume managed as a secondary volume, wherein when the disk array system receives a write request of data to the first logical volume and data to be written from the information processing apparatus, the disk control apparatus is configured to: write the data into the first logical volume; and write a journal data into the third logical volume, the journal data comprising, information of a location in which the data is stored in the first logical volume, update time and the data, wherein the disk control apparatus is configured to: refer to an update time for each of a plurality of journal data stored in the third storage device: select at least one journal data, among the plurality of journal data, for which a difference between current time and the update time of the selected at least one journal data thereof is longer than a predetermined time; and write data of each of the at least one selected journal data into a place corresponding to respective location information in the second plurality of disk drives in order of the update times of each of the selected journal data, write split order data into the third logical volume, in response to receiving a split ordering instruction from the information processing apparatus, the split ordering instruction interrupts writing the data into the second logical volume, the split order data comprising data indicating that the split ordering instruction has been received, and split time; and write split cancel data into the third logical volume, in response to receiving a split canceling instruction from the information processing apparatus, the split canceling instruction resuming writing the data into said second logical volume, the split cancel data is data indicating that the split canceling instruction has been received, wherein, if the split order data is stored in said third logical volume and the split cancel data is not stored in said third logical volume, the disk control apparatus does not write the data in a journal data having an update time later than the split time into the second logical volume based on referring to the split time in the split order data.