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)