System software

OAM is a component of DFSMSdfp and uses DB2 extensively. CICS and IMS transactions, TSO/E programs, and MVS batch jobs can invoke the OSREQ application programming interface (API) to OAM.

Restrictions: Consider the following restrictions when planning for the installation of OAM:

Only one OAM address space can be active per z/OS system.
Only one DB2 subsystem application can be associated per OAM address space.
Optical devices can only be directly accessed by the OAM address space where they are physically online; however, they can be indirectly accessed by other OAMs within an OAMplex.
If in an OAMplex, the DB2 subsystems connected to the OAMs in the OAMplex must belong to the same DB2 data sharing group.

Related reading: See z/OS DFSMS OAM Application Programmer's Reference for additional information on the OSREQ API.

To process objects greater than 256MB on the file system sublevel or on tape, the OAM address space uses 64–bit addressing and virtual storage above the 2G bar. Additional configuration may be required to specify a MEMLIMIT value that will provide virtual storage above the 2G bar to the OAM address space. For more information see MEMLIMIT for OAM.