When
you activate an SCDS, its contents are copied to an ACDS. The current
ACDS contains a copy of the most recently activated configuration.
All systems in an SMS complex use this configuration to manage storage.
You can define any number of SCDSs, but only one can be put in the
ACDS. z/OS MVS Initialization and Tuning Guide explains
how to specify the ACDS. You can define more than one IGDSMSxx member,
each specifying a different ACDS, but you can use only one ACDS at
a time.
Tip: You can save the current ACDS as
an SCDS using the SETSMS SAVESCDS command. You can also create an
ACDS from a SCDS with the SETSMS COPYSCDS command. For more information,
see
Parameters of the SETSMS operator command.
Restriction: You cannot define or alter
an ACDS. This also means that you cannot use an ACDS as an SCDS if
the SCDS is lost.
You can modify the SCDS from which your current storage management
policy was activated without disrupting operations, because SMS manages
storage with a copy of the SMS configuration (an ACDS) rather than
with the original (an SCDS). While SMS manages storage using an ACDS,
you can:
- Create
a backup copy of the SCDS
- Build a new SCDS
- Update the SCDS from which the ACDS was activated
- Modify any SCDS
Figure 1 shows
the relationship among SCDSs and ACDSs in an installation.
Figure 1. Relationship
among SCDSs and ACDSs in an Installation