Each installation defines a storage management policy that allows
effective object storage management without requiring user intervention.
Using ISMF, the storage administrator and system programmer define
an installation storage management policy in an SMS configuration.
OAM manages object storage according to the active policy. Disk (DB2
tables or file system), optical, and tape can all be used as the primary
storage media for storing objects. Backup copies of objects can only
be stored on optical or tape volumes. See
Figure 1 for
a pictorial overview of this process.
Figure 1. Overview of the Installation Storage
Management Policy
An SMS configuration consists of the following elements:
- Base configuration. The base configuration
identifies the systems in an SMS configuration and contains installation
defaults. It also applies to SMS-managed data sets as well as objects.
Only object-related functions are discussed in this document.
- Active control data set (ACDS). The ACDS
controls the storage management policy for the installation.
- Automatic class selection (ACS) routines. The
storage administrator uses the ACS routines to assign storage group,
storage class, management class, and data class constructs to data
sets or objects that are based on customer-defined criteria. ACS routines
are invoked with user-input variables, and they make decisions based
on the environment called. The ACS routines use input values to set
new values which causes changes in the SMS handling of the data.
- Optical library and optical drive definitions. Optical
storage hardware must be defined to the system through ISMF before
it can be used. (Tape drives are dynamically allocated for use when
required. They are defined to the system through the use of the Hardware
Configuration Definition [HCD], not ISMF.)
- OAM configuration. OAM stores the optical
library and drive definitions in the OAM configuration database (DB2)
and in the ACDS through the SMS constructs.
- SMS constructs. Constructs are lists of
attributes that are assigned to objects and storage areas. An SMS
configuration can contain the following types of constructs. However,
OAM uses only four of them (storage group, storage class, management
class, and data class) to manage object storage. An SMS configuration
can contain multiple constructs of each type.
- The Storage group construct allows you to
define a storage hierarchy and manage that hierarchy as if it were
one large, single storage area. See Understanding the storage group construct for information
on establishing and manipulating storage groups.
- The Storage class construct allows you to
define different levels of performance objectives and availability
requirements for objects. See Understanding the storage class construct for information
on assigning an object to a storage class.
- The Management class construct allows you
to define backup, retention, and class transition attributes for objects.
See Understanding the management class construct for specific information on defining the
management class attributes.
- The Data class construct allows you to define
specific data attributes that are required for your installation's
tape storage. See Understanding the data class construct.
- Aggregate group allows you to group a collection
of data objects to prepare for disaster recovery, application transfer
or archiving, or data migration. An aggregate groups allows the data
to be referred to collectively or individually. OAM does
not use aggregate groups.
- A copy pool is a defined set of storage
groups that contain data that DFSMShsm can
back up and recover collectively using fast replication. OAM does not use copy pools.