Applicants' automated data storage system includes a first media storage library having a first rail system, a garage having a movable rail system, said garage being disposed adjacent the media storage library, and a plurality of accessors movably disposed on either the first rail system or the movable rail system. In another embodiment, Applicants' automated data storage system further includes a second media storage library, having a second rail system, disposed adjacent the garage, such that the plurality of accessors is movably disposed on the first rail system, the second rail system, or the movable rail system. Applicants' invention further includes a method to move an accessor from the first media storage library into the garage, or from the first media storage library, through the garage, and into the second media storage library. Applicants' invention further includes a method to balance the workload of a plurality of data drives disposed within Applicants' automated data storage system.