Patent ID: 11886300
Assignee: HITACHI, LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 6:
7. A backup method for a data replication system comprising a first storage having a first volume for reading and writing data by an external device, and a first data protection area for storing backup images of multiple generations of the first volume and the first data protection area cannot be accessed by external devices, a second storage being coupled to the first storage, the method comprising the steps of:
the first storage:
creates a second volume for providing backup image of a particular generation of the multiple generations of the first volume stored in the first data protection area; and

the second storage:
creates a third volume for storing data comprising the backup image of the particular generation of the first volume provided by the second volume;
creates a first virtual volume forming a pair that copies the data of the backup image of the particular generation to the third volume;
makes the second volume accessible via the first virtual volume by mapping the first virtual volume as an external source and the second volume as an external destination;
reads a backup image of the second volume through the first virtual volume by copying data from the first virtual volume to the third volume; and
stores the data comprising the backup image of the particular generation of the first volume in said third volume by writing to said third volume.