By managing storage with SMS, you establish the following:
- Storage classes to define levels of service provided to data sets
- Storage groups to govern the volumes to which data sets are allocated
and subject to management by DFSMShsm
- Storage groups to define which volumes are used as target volumes
of the fast replication backup versions
- Management classes to define how DFSMShsm manages the data sets
- Data classes to govern values for initially allocating the data
sets
- Automatic class selection (ACS) routines that automatically select
storage classes, management classes, data classes, and storage groups
to govern the data sets
DFSMShsm is concerned mainly with DASD storage groups and with
management classes. DASD storage groups allow you to pool volumes
for the purpose of defining how and whether:
- Automatic dumps are performed on the volumes and to what dump
classes
- Automatic backups are performed on the volumes
- Automatic volume space management is performed on the volumes
and at what level of occupancy
Management classes allow
you to group data sets logically and specify how they are managed
by space management and availability management.
As users allocate data sets, the automatic class selection routine
associates them with the appropriate storage class, storage group,
management class, and data class (data and management classes are
optional). If a data set is not SMS managed, SMS does not associate
any class or storage group with the data set.
The storage group and the management class are related only by
the needs of particular data sets. That is, SMS can allocate data
sets that are associated with different management classes to the
volumes assigned to a single storage group. Thus, in using DFSMShsm
to manage SMS-managed storage, you must think in terms of managing
data sets rather than in terms of managing volumes. (An exception
to the preceding statement is the automatic dump function, which operates
on a volume basis.)