Patent ID: 8862844

Claim:
A backup apparatus for producing backup volumes of a plurality of generations regarding a backup target volume, comprising: a storage section adapted to store the backup volumes of the plural generations; a first production section adapted to copy data in the backup target volume at a point of time at which a production instruction of a backup volume of a first generation is received into a region for the first generation of said storage section to produce the backup volume of the first generation; a first monitoring section adapted to monitor, as a first update region, a region to which the data updated in the backup target volume after a production instruction of a backup volume of an i−1th generation is issued belongs, i being a natural number equal to or greater than two; a second monitoring section adapted to monitor, as a second update region, a region to which the data updated in the backup volume of the i−1th generation belongs after a production instruction of the backup volume of the i−1th generation is issued; and a second production section adapted to refer, if a production instruction of a backup volume of an ith generation is received, to the first update region monitored by said first monitoring section and the second update region monitored by said second monitoring section to secure, in said storage section, a region for the ith generation having a capacity corresponding to capacities of the first update region and the second update region, and then copy the data in the first update region and the data in the region corresponding to the second update region in the backup target volume at a point of time at which the production instruction of the backup volume of the ith generation is received into the region for the ith generation to produce the backup volume of the ith generation.