ISO/ANSI installation exits

Four ISO/ANSI installation exits are provided, as defaults, for a Version 3 or a Version 4 volume:

Volume access
File access
Label validation
Label validation suppression

A fifth installation exit, WTO/WTOR, can be written (or modified, if one has already been written) by your installation to convert ISO/ANSI non-Version 3 to Version 3 labels.

All the default installation exit routines are supplied in a module containing a single CSECT (IFG0193G, alias IFG0553G), in SYS1.LPALIB. A copy of the source code for the module is contained in member ANSIEXIT of SYS1.SAMPLIB.

The default routines, except the validation suppression exit, reject the volume. Your system programmer can replace any of the IBM-supplied exit routines with your own, installation-written, exit routines. The default routines can be modified or replaced to perform I/O (such as overwriting a label), change system control blocks, and mount or demount volumes. The return code from the exits can be modified to request continued processing.

For detailed information about these and other available exit routines, see z/OS DFSMS Installation Exits.