Planning management classes

You should create a management class for each type of service that is to be provided by the installation. A type of service is defined for a collection of data sets that have similar migration, backup, and retention requirements or objects that have similar backup, expiration, and class transition requirements. Before you actually define your management classes, you should gather the following information:

Requirements for releasing over-allocated space
Migration requirements
Retention criteria
Treatment of expired data sets
Frequency of backup
Number of backup versions
Retention of backup versions
Number versions
Retain only version
Retain only version unit
Retain extra versions
Retain extra versions unit
Copy serialization
Generation data group (GDG) information
Class transition criteria
Transition copy technique
Serialization exit

Based on this information, you can establish management classes that centralize storage management in the SMS complex.

If a data set has a management class that specifies automatic backup, migration, or transitions, then you must direct the data set to storage groups that are eligible to be processed for automatic backup or migration capabilities.

A generation data group (GDG) is a group of related cataloged data sets that have sequentially ordered names. SMS uses GDG-related information in the management class definition to manage the storage associated with these data sets. Some management criteria is specified in the definition of the GDG. Some management criteria might be specified by assigning a management class to each individual generation in the GDG. Generation data sets within the same GDG might have different management classes assigned by JCL.

DFSMSrmm uses management class names, instead of attributes, for tape data set retention and movement. It matches a management class name with a DFSMSrmm vital record specification (VRS) and implements the policies defined in the VRS.