ABCs of z/OS System Programming Volume 3 - IBM Redbooks

5.7 Assigning data to be system-managed
Data Set
Figure 5-7 How to be system-managed
How to be system-managed
Using SMS, you can automate storage management for individual data sets and objects, and
for DASD, optical, and tape volumes. Figure 5-7 shows how a data set, object, DASD volume,
tape volume, or optical volume becomes system-managed. The numbers shown in
parentheses are associated with the following notes:
1. A DASD data set is system-managed if you assign it a storage class. If you do not assign a
storage class, the data set is directed to a non-system-managed DASD or tape volume,
one that is not assigned to a storage group.
2. You can assign a storage class to a tape data set to direct it to a system-managed tape
volume. However, only the tape volume is considered system-managed, not the data set.
3. Objects are also known as byte-stream data, and this data is used in specialized
applications such as image processing, scanned correspondence, and seismic
measurements. Object data typically has no internal record or field structure and, after it is
written, the data is not changed or updated. However, the data can be referenced many
times during its lifetime. Objects are processed by OAM. Each object has a storage class;
therefore, objects are system-managed. The optical or tape volume on which the object
resides is also system-managed.
4. Tape volumes are added to tape storage groups in tape libraries when the tape data set is
created.
250 ABCs of z/OS System Programming Volume 3
DASD Optical Tape
Assign Storage
Class (SC)
Not applicable
Not
system-managed
Object Stored Stored Stored
Volume
(3)
(1)
Assign System
Group (SG)
Define OAM
Storage Groups
(SG)
(2)
(4)
Assign
Storage Group
(SG)