This section discusses the steps that are necessary when tape subsystems are added, moved or deleted. A cable change within a library that switches ports so that existing subsystems are now associated with different subsystem IDs should be treated as if the subsystems had been physically moved.
For an existing library, before modifying the subsystem configuration, use the VARY SMS command to VARY the library offline to each attached host. After the necessary IODF ACTIVATEs or optional IPL, use the LIBRARY DISPDRV command to verify that the correct number of devices appear in the library configuration and that no device appears multiple times in the display for that library.