System-managed storage for data and space management

OAM is a component of DFSMSdfp™, the base for the Storage Management Subsystem (SMS). OAM uses system-managed storage, which provide functions for data and space management. SMS provides the following benefits:

Manages storage growth
Improves the use of storage space
Reduces the effort of device conversion and coexistence
Provides centralized control of external storage
Exploits the capabilities of available hardware

Use SMS to define a storage hierarchy for objects and the parameters for managing those objects. OAM uses this hierarchy definition and management parameters to place user-accessible objects anywhere in the SMS storage hierarchy.

Figure 1. Object storage hierarchy

The object storage hierarchy can consist of:

Disk sublevel 1, which is associated with DB2 tables on a direct access storage device (DASD). The following object storage DB2 tables provide disk sublevel 1 storage for objects:
- 4 KB storage table
- 32 KB storage table
- LOB storage structure
Disk sublevel 2, which is associated with an NFS or z/FS file system.
Tape sublevel 1 volumes associated with a tape library device (SMS-managed, library-resident tape volumes), and tape volumes outside of a library device (non-SMS-managed, shelf-resident tape volumes)
Tape sublevel 2 volumes associated with a tape library device (SMS-managed, library-resident tape volumes), and tape volumes outside of a library device (non-SMS-managed, shelf-resident tape volumes)
Optical volumes inside a library device (SMS-managed, library-resident optical volumes), and optical volumes outside of a library device (SMS-managed, shelf-resident optical volumes)