z/OS V1R8 DFSMS Technical Update - IBM Redbooks

RLS use in general, and the 64-bit requirements in particular being dropped.
Refer to “OA18319” on page 462 for further information.
3.6.7 Monitoring the VSAM RLS use of 64-bit data buffers
You can monitor the use of VSAM RLS 64-bit data buffers, and check on the status of data
classes eligible and which data sets are eligible.
You can set up recording of SMF type 42 records then check the data returned in the
appropriate subtype records as listed below. For more information refer to Chapter 7 under
“Monitoring the use of 64-bit data buffers,” in the manual DFSMS Using the New Functions,
SC26-7473.
If you have access to IBM RMF then it is preferable to use it to look at the various statistics
provided. If you do not have RMF then the sample programs provided in the appendix and
illustrated below can be used to gain insight into what is happening on the system.
Note: Before using any of the SMF records for analysis, review the current status of APAR
OA17704, as shown in “OA11708” on page 457.
SMF records for analysis
The SMF records for analysis are:
► SMF Record type 42 Subtype 16 (Data Set Summary) indicates whether a data set is
enabled for 64-bit data buffers and whether it uses storage above 2-gigabytes. Any data
set that you want SMF to monitor usage for must be nominated by means of the
command:
V SMS,MONDS(datasetname),ON
Where datasetname is a fully qualified name or one with one trailing asterisk (*).
For details on these SMF records for analysis refer to 3.6.8, “SMF Record type 42 Subtype
16 information example” on page 30.
► SMF Record type 42 Subtype 18 (CF Cache Partition Usage) provides statistics on the
use of coupling facility cache storage classes. For details on these SMF records for
analysis see “SMF Record type 42 Subtype 18 information example” on page 36.
► SMF Record type 42 Subtype 19 (LRU record) provides statistics for data buffers above
and below 2 gigabytes. For details on these SMF records for analysis see “SMF Record
type 42 Subtype 19 information example” on page 44.
3.6.8 SMF Record type 42 Subtype 16 information example
SMS writes SMF Record type 42 subtype 16 to document VSAM RLS data set activity.
Note: Before attempting to use SMF type 42 subtype 16 records in relation to 64-bit buffer
usage, APAR OA17704 (see “OA17704” on page 456) should be installed.
We wrote a simple program called SMF42TG to scan the SMF records and summarize
activity. The program itself and how to construct it are documented in “SMF record type 42
subtype 16 data display program” on page 522.
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