Before you define your tape library, consider the tape subsystem characteristics of the devices in the tape library dataserver and their ability to support media interchange attributes-recording technology modes and media types required to support your tape data.

Volumes inserted in the tape library dataserver can automatically be assigned values for recording capability, media type, and compaction with the Entry Default Data Class. Or, you can supply this information in the cartridge entry installation exit or through DFSMSrmm.

Initially, the volumes in your tape library might be scratch volumes, private volumes, or a combination of both types of volumes. Enter the predominant type of use attribute, Private or Scratch, in the Entry Default Use attribute.

When you or DFSMShsm eject volumes from the tape library dataserver, the volume entry in the tape configuration database can be retained or purged. Use the Eject Default to set this attribute to Keep or Purge based on your requirements. If you expect volumes to be reused in the library, use the default value, Keep, for this attribute.

When you use DFSMSrmm to eject volumes from the tape library dataserver, the entry in the tape configuration database is optionally purged. DFSMSrmm has all the information needed to recreate the entries when the volumes are returned for reuse.

Related Reading: For more information about using DFSMSrmm, see z/OS DFSMSrmm Implementation and Customization Guide.