Log stream sizing

To decide how much storage you need in a coupling facility, you must estimate the size of the log streams that you will store in it. Estimate a size for each of the logs that DFSMStvs uses:

Primary system log for SMSVSAM
Secondary system log for SMSVSAM
Forward recovery logs
Log of logs
Log streams for RRS
Primary system log for CICS®
Secondary system log for CICS

You can use the DFHLSCU utility, which CICS supplies, to help calculate the amount of coupling-facility space that you need and the average buffer size of your log streams.

Related reading:

For information about how to use the DFHLSCU utility, see http://publib.boulder.ibm.com/infocenter/cicsts/v3r1/index.jsp
For more information about estimating the size of log streams, see Parallel Sysplex Configuration, Volume 2: Cookbook.