Automated Tape Libraries and Virtual Tape Support › The IBM Tape Library

The IBM Tape Library

The IBM TotalStorage Tape Library is IBM's main cartridge tape library for the mainframe. The IBM Tape Library also supports connectivity to open systems and is the framework for IBM's virtual tape system, the IBM TotalStorage Virtual Tape Server (VTS).

This section describes how to configure CA 1® Tape Management with the IBM Tape Library when managed by OAM and with host-attached physical devices. For more information about configuring CA 1® Tape Management with IBM VTS, see the section IBM Virtual Tape Server later in this chapter. The IBM Tape Library may also be configured in Basic Tape Library Support (BTLS) mode, in which case the OAM exits are not installed. For information on managing an IBM Tape Library in BTLS mode, see the section IBM Basic Tape Library Support (BTLS) later in this chapter.

Integration between CA 1 and the IBM Tape Library or the IBM VTS is based on four exits/options that are used to communicate with the robot:

• CBRUXENT—IBM OAM Volume Entry (Usermod CTSJUCBX)
• CBRUXEJC—IBM OAM Volume Eject (Usermod CTSJUCBX)
• CBRUXVNL—IBM OAM Volume Not In Library (Usermod CTSJUCBX)
• ROBSCR—CA 1 option (see member TMOOPTxx) to notify OAM when a tape volume is scratched.

Object Access Method (OAM) is a part of IBM's DFSMSdfp component and is designed to provide management of data objects rather than files. OAM is also used to manage IBM's tape libraries as part of an overall storage hierarchy, based on DFSMS System Managed Storage concepts and facilities. The OAM address space also maintains the Tape Configuration Database (TCDB), which defines the IBM tape volumes and libraries that are managed. The TCDB is made up of one or more VOLCATs, a special type of ICF.CATALOG which is specifically marked as a volume catalog.

OAM includes a component, Library Control Services (LCS) which is used to manage the movement and tracking of tapes in IBM automated tape libraries. CA 1 interfaces to OAM through requests made to LCS.

There are four basic functions available to support the IBM ATL with the current version of CA 1:

1. Ensure that the status of new cartridges entering the IBM ATL are correct
2. Synchronize the CA 1 TMC and the IBM ATL database (TCDB)
3. Eject any cartridges that are needed for off-site storage from the IBM ATL.
4. Change the status of cartridges as they are scratched.

These functions are accomplished in different ways depending on whether the IBM ATL is managed as an SMS managed tape device or using the much less common Basic Tape Library Support (BTLS).

To configure your installation to access the IBM ATL as an SMS managed tape library, you must customize the OAM exits CBRUXENT and CBRUXEJC. The CBRUXVNL exit is optional. The details of each process are described in the following section.

Note: Additional calls to these exits are performed when an IBM VTS is being managed. The additional calls related to virtual tape processing are discussed in the section IBM Virtual Tape Server (VTS) later in this chapter.