A storage area managing apparatus includes a managing unit for managing a plurality of logical volumes provided by a plurality of storage drive groups for storing data redundantly, and a rebuilding controller for generating recovery data when at least one of the drive groups is degraded on the basis of the data stored in the degraded drive group and generating a selected logical volume on the basis of the capacity of the recovery data, the rebuilding controller controlling the management unit for managing first logical volumes to correspond to a part of the plurality of storage drive groups except for the degraded drive group. The storage area managing apparatus includes a first transferring unit for transferring the recovery data to the part of the plurality of storage drive groups as indicated by the selected logical volume.