Patent attributes
A backup acquisition method and a disk array apparatus for implementing the method are provided for acquiring a whole or a differential backup from a disk array apparatus to a backup device. A snapshot of the contents of disks in the disk array apparatus is captured in response to a snapshot capture instruction to the disk array apparatus. Updated data is sequentially recorded after the capture of the snapshot separately into a pre-update data storage area of the disk array apparatus from the beginning. The disk array apparatus is instructed to acquire a whole or a differential backup at an arbitrary timing. The whole areas or used areas of disks in the disk array apparatus are sequentially read to acquire a whole or differential backup into the backup device.