Tape libraries consist of a set of tape volumes and the set of tape drives on which those tape volumes can be mounted. A tape library can consist of one or more tape subsystems. These drives are configured into automated or manual tape library dataservers that contain library-resident tape volumes. The storage administrator defines tape libraries to SMS using ISMF library management definition panels. A tape library can contain tapes from multiple storage groups and a storage group can span up to eight libraries (ATLDSs, MTLs, or a combination of these).
Related reading: For more information on defining tape libraries, see z/OS DFSMS OAM Planning, Installation, and Storage Administration Guide for Tape Libraries.