Choosing the right attributes is the key to facilitating post-processing
of large stand-alone dumps and large SVC dumps. IPCS is used to consolidate
and extract ASIDs from the dump, format, and analyze the dump. IPCS
uses a dump directory to maintain information about the layout and
content of the dump. The dump directory is a VSAM data set that you
can tune for optimal performance.
You can improve IPCS performance by reducing the number of control
interval (CI) splits during initialization and analysis of dumps.
To do this, specify the RECORDSIZE parameter in BLSCDDIR (shipped
in SYS1.SBLSCLI0). The RECORDSIZE parameter in BLSCDDIR is ‘RECORDSIZE
(2560 3072)’ and yields well performing CISIZEs for the data portion
of the data set. To allow IPCS to be more efficient in its processing,
it is recommended that you delete old dump references from the directory
periodically (especially stand-alone dumps).
Note: - When IBM® System Test uses
BLSCDDIR, they specify a CI size of 24,576 and a BUFSPACE of X'100000'.
- You can tune the RECORDSIZE parameter by observing the number
of CI splits using standard VSAM data set analysis techniques, such
as the LISTCAT command.