Sharing a database

See Shared database considerations for important considerations that apply even within a sysplex.

RACF® is designed so that its database can be shared between processor complexes while data integrity is maintained. Because of the need to serialize RACF database processing, there might be some I/O contention. RACF sysplex data sharing is designed to address the problems that can occur when many systems share a RACF database. Sharing the RACF database requires that:

The database reside on shared DASD.
The data set name table (ICHRDSNT) is compatible on all sharing systems.
The database range table (ICHRRNG) is identical on all sharing systems.
The class descriptor table (ICHRRCDE) is compatible on all sharing systems.

z/OS® and z/VM® systems can share a RACF database. However, you must not share outside the sysplex if you choose to use data sharing mode (see Sharing a database with sysplex communication in data sharing mode), nor outside of a single global resource serialization complex if you choose to convert the SYSZRACF RESERVE to an ENQ using the z/OS global resource serialization reserve conversion RNL.

Many SETROPTS options (for example SETROPTS CLASSACT) automatically take effect across sharing systems when the inventory control block (ICB) of the master primary RACF data set is read on the other systems. Other SETROPTS commands (for example SETROPTS RACLIST) must be issued explicitly on all sharing systems. RACF sysplex communication performs command propagation for certain commands (for example SETROPTS RACLIST). You do not have to issue these commands on each system sharing the database. Instead, you can issue a command once, and RACF propagates it to the other systems in the sysplex. For more information on command propagation, see Sysplex communication.