You can associate a storage class with a CF cache set that is defined
in the base configuration, thereby making any data set associated
with the storage class eligible for VSAM record-level sharing. You
can also assign a weight value to the data, so as to indicate its
relative importance. You should be familiar with the information in
the following topics:
Specify values for the following attributes:
- Multi-Tiered SG
- Specify Y if you want SMS to prefer the storage group sequence
order as specified in the ACS storage group selection routines. ISMF
primes the field with the default N, No.
- Parallel Access Volume Capability
- Specify R for required, P for preferred, S for standard, and
N for no preference. The default is N.
- CF Cache Set Name
- Is the name of a CF cache set that is defined in the base configuration.
When
you specify a cache set name, any data set associated with this storage
class becomes eligible for record-level sharing using the CF. CACHE
SET NAME maps the storage class to a CF cache set defined in the SMS
base configuration, for which CF cache structures have been defined.
In
a JES3 environment, be careful to define cache set names only in those
SMS storage classes that are used by data sets opened for VSAM RLS
processing. When you define a cache set name in a storage class,
any job accessing a data set associated with that storage class is
scheduled on a VSAM RLS-capable system. If all storage classes have
cache set names defined for them, then all jobs accessing SMS-managed
data sets are scheduled to VSAM RLS-capable systems. This could cause
a workload imbalance between those systems and down-level systems.
- CF Direct Weight or the CF Sequential Weight
- Specify a weight attribute indicating the data's relative importance.
Use the CF Direct Weight field for direct data; use the CF Sequential
Weight field for sequential data. The default is a weight value of
6.
Restriction: DFSMS supports only the default value. All data is assigned
a weight value of 6 regardless of the value you specify.
z/OS DFSMSdfp Storage Administration
Copyright IBM Corporation 1990, 2014