StorageManagementwith DFSMS 37
1. Data Class—data definitionparameters.
2. Storage Class—performanceand accessibilityr equirements.
3. Management Class—migration,backup and retention attributes.
4. Storage Group—candidate allocation volumes.
Because data set allocations,whet her dynamicor t hrough JCL, areprocessed
through ACS routines,installation standards can be enforced on those
allocations on both SMS and non-SMS managed volumes.ACS routines permit
user defined specifications for Data, Storage, and Management Classes, and
requests for specificvolumes, to be overridden, thereby offering more control of
where data sets are positioned within the system.
For a data set to qualify forSMS m anagement, it must satisfyt he Storage Class
component. If a valid Storageclass is assigned, then the data set is managed by
SMS, and proceeds via the Management Class and Storage Group routines
beforebeing al locatedon a SMS volume.I f a null Storage classis assigned, the
data set exitsfrom the process, is not managed by SMS, and is allocated on a
non-SMS volume.
Figure 12 on page 37 shows the executionprocess for defining data sets in an
MVS system (with SMS active).
Figure 12. ACSRoutine Execution Proce ss
ACS Routine Process
Procedure
(DFSMSdss/hsm)
New Allocation
Data Class
Non-SMS
Managed
Storage Class
Management
Class
Storage
Group
SMS
Managed
Conversion SC=NULL
SC=&STORCLAS