Patent ID: 7069277

Claim:
A backup management device that manages multiple generations of backup data by rotating a plurality of rewriteable backup media while recording backup data onto the backup media according to a predetermined backup cycle, the backup management device comprising: a save period input unit that receives save periods for which the backup data should be saved, the save period being individually set by the administrator for each of the multiple generations; an overwrite-targeted backup medium selecting unit that selects an overwrite-targeted backup medium on the basis of the backup cycle and the save period; a backup executing unit that executes new generation backup by overwriting the selected overwrite-targeted backup medium, and when a decision is that overwriting is not possible, prepares a new backup medium and executes first generation backup, or issues a warning to the user; a save period storage unit that stores the save period; and a medium information storage unit that stores information regarding the backup medium and the time at which the backup data was stored in the backup, in association with one another, wherein the overwrite-targeted backup medium selecting unit comprises: a decision unit that refers to the save period storage unit and the medium information storage unit, and when generation n (n is a natural number) backup data moves to a save period (m+1) one period older than a save period m to which the generation n belongs, decides whether first generation backup data is overwriteable onto the backup medium in which the backup data was stored; and wherein the decision unit compares a first predetermined time interval until generation (n−1) backup data one newer than the generation n backup data moves to the save period (m+1) with a second predetermined time interval until the generation (n+1) backup data leaves the save period (m+1), and when the first predetermined time interval is equal to or shorter than the second predetermined time interval, decides that the backup medium storing the generation n backup data is overwriteable.