After performing the initial verification
of your IMS environment, you
can enable dynamic resource definition (DRD) for MODBLKS resources
with a resource definition data set (RDDS).
To enable dynamic resource definition (DRD)
for MODBLKS resources with a resource definition data set (RDDS):
Procedure
- Shut down IMS normally.
- Change MODBLKS=OLC to MODBLKS=DYN in either the COMMON_SERVICE_LAYER
section of the DFSDFxxx member or in the DFSCGxxx member in the IMS PROCLIB data set.
- Specify the following keywords in the DYNAMIC_RESOURCES
section of the DFSDFxxx member of the IMS PROCLIB
data set:
- AUTOEXPORT=AUTO or AUTOEXPORT=RDDS
- AUTOIMPORT=AUTO or AUTOIMPORT=RDDS
- RDDSDSN=(rdds1,rdds2,rdds3)
- Use either the IEBGENER program or the ALLOCATE function
of ISPF utilities to allocate the RDDS data sets.
- Cold start IMS,
specifying DFSDF=xxx in the control region
execution parameters, where xxx identifies
the suffix of the DFSDFxxx member in the IMS PROCLIB data set that IMS uses for this startup.
IMS loads the resource definitions
from the IMS.MODBLKS data set
because the defined RDDSs are empty. The IMS.MODBLKS
data set is used only the first time you implement DRD, except for
fallback purposes. IMS uses the
resource definitions to create the internal control blocks required
to manage the resources. When the initial checkpoint is taken, the
resource definitions are automatically written out to one of the defined
RDDSs because AUTOEXPORT=AUTO is specified. Also, because AUTOIMPORT=AUTO
is specified and the RDDSs are no longer empty, IMS loads its resource and descriptor definitions
from the RDDS with the most current data the next time that IMS coldstarts.
Restriction: After IMS starts
with DRD enabled, you can no longer use the online change process
to add, change, or delete database, application program, route code,
or transaction resource definitions.