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.

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.