If at IPL RACF® does not find an installation-supplied data set name table (and the master JCL does not point to a RACF database with a SYSRACF DD statement), RACF prompts not only for a primary RACF database, but also for a backup database. However, this results in a primary database with only 10 data blocks, an inactive backup database, and poor system performance.

Guideline: Use a data set name table instead of MSTJCLxx, because MSTJCLxx recognizes only the primary database when the SYSRACF DD statement is provided.