A rack storage system with a rack storage with storage racks (12a, 12b), which have storage locations for loads at rack levels located one above another, and a load manipulation unit (4""), which comprises at least one first load lifting device (34a; 84a) with a transport device (36a; 86a), which can be raised and lowered, for the storage and retrieval of loads, together with a first buffer device (35a; 85a) with provisioning devices (43, 44) for the temporary storage of one or a plurality of loads, and at least one rack aisle extending between storage racks (12a, 12b) arranged adjacent to one another and along the load-lifting device (34a; 84a) together with the first buffer device (35a; 85a), and guide tracks running in at least some of the rack levels along the rack aisle, and one or more autonomous conveyor vehicles that can traverse along the guide tracks for purposes of transporting the loads between the storage locations of the storage racks (12a, 12b) and the provisioning devices (43, 44) of the load manipulation unit (4""), and a conveying system (106a, 107a) connected to the load-lifting device (34a; 84a) for purposes of transporting loads to and from the load-lifting device (34a; 84a), wherein the conveying system comprises a first conveying device for purposes of transporting loads to the load-lifting device (34a; 84a) and a second conveying device for purposes of transporting loads from the load-lifting device (34a; 84a), which first and second conveying devices (106a, 107a) are essentially arranged one above another on a level with the corresponding rack levels and extend into the extension of a storage rack (12a, 12b), and wherein the buffer device (35a; 85a) in at least some of the rack levels comprises a first fixed buffer path section and a second fixed buffer path section, in which the provisioning devices (43, 44) are arranged, and wherein the load-lifting device (34a; 84a) is arranged such that its transport device (36a; 86a) for purposes of storing and retrieving loads can be vertically positioned relative to the rack levels, either between two oppositely located provisioning devices (43, 44), or at the front face in front of one of the conveying devices (106a, 107a), such that a load can either be conveyed between the transport device (36a; 86a) and one of the provisioning devices (43, 44) or between the transport device (36a; 86a) and one of the conveying devices (106a, 107a), and wherein the provisioning devices of the first buffer path section each form a removal path for the loads in all rack levels in which these are arranged, and the provisioning devices of the second buffer path section each form a storage path for the loads in all rack levels in which these are arranged, and wherein in a conveying section adjacent to the load-lifting device (34a; 84a) at least one of the conveying devices (106a; 107a) also comprises a provisioning device (108; 110) for the temporary storage of one or a plurality of loads, wherein the provisioning devices (43; 44, 108; 110) are located opposite one another on both sides of the load-lifting device (34a; 84a), characterised in that the guide tracks in those rack levels in which the provisioning devices (43, 44) are arranged, and the guide tracks in at least one of the rack levels, in which the conveying devices (106a; 107a) are arranged, extend continuously along the rack aisle and the load-lifting device (34a; 84a) together with the provisioning devices (43, 44, 108; 110), such that in the respective rack level, in which the provisioning devices (43, 44) are arranged, either the provisioning device in the first buffer path section or the provisioning device in the second buffer path section can be approached by the conveyor vehicle via the guide tracks for purposes of the retrieval and storage of loads, and in at least one of the rack levels, in which the conveying devices (106a; 107a) are arranged, either the provisioning device (43; 44) of the buffer path section (41a; 42a) or the provisioning device (108; 110) of the conveying device (106a; 107a) can be approached by the conveyor vehicle via the guide tracks for purposes of the retrieval and storage of loads.