In a WORM optical-storage subsystem that the Optical Subsystem supports, the optical media are organized into units of storage called the volume and the family. Each side of the platter is called a volume. An optical family is theoretically an unlimited collection of volumes, although in practice the constraints of the optical-storage subsystem impose a limit on its size. When a volume becomes full, the optical-storage subsystem automatically allocates another volume for the family.
The optical-storage administrator creates an optical family with the management software that the vendor of the optical-storage subsystem provides. The administrator also uses optical-storage subsystem commands to add volumes to a family.
In a manner that is similar to an automated tape library, the optical-storage subsystem tracks the location of each TEXT and BYTE data object on a volume, each volume on a platter, and each platter in a family. Subsystem software schedules the optical drives and mounts platters as needed.
Figure 1 shows the relationship between the optical family, the volume, and the optical platter.