EXITxx (allocation installation exit list)

Use the EXITxx member of SYS1.PARMLIB to specify the following installation exits for the following allocation decisions.
Volume ENQ
When a job must wait to enqueue on a volume or a series of volumes, code the volume ENQ exit routine to make exceptions, if any, to the installation default policy for certain jobs and/or volumes. See ALLOCxx (allocation system defaults) for information about specification of the installation default policy. See z/OS MVS Installation Exits for information about coding the volume ENQ installation exit.
Volume Mount
When a job's allocation request requires a volume to be mounted, code the volume mount exit routine to make exceptions, if any, to the installation default policy for certain jobs and/or volumes. See ALLOCxx (allocation system defaults) for information about specification of the installation default policy. See z/OS MVS Installation Exits for information about coding the volume mount installation exit.
Specific Wait
When a job must wait for a specific volume or device to become available, code the specific waits exit routine to make exceptions (for certain jobs and/or volumes) to the installation default policy. See ALLOCxx (allocation system defaults) for information about specification of the installation default policy. See z/OS MVS Installation Exits for information about coding the specific waits installation exit.
Allocated/Offline Device
When a job must wait because the device it requested is offline or allocated to another job, code the allocated/offline device exit routine to make exceptions, if any, to the installation default policy for certain jobs and/or devices. See ALLOCxx (allocation system defaults) for information about specification of the installation default policy. See z/OS MVS Installation Exits for information about coding the allocated/offline device installation exit.
Note: IBM® provides the PROGxx parmlib member as an alternative to EXITxx. PROGxx allows you to specify exits, control their use, and associate one or more exit routines with exits, at IPL or while the system is running. IBM suggests that you use PROGxx to specify exits whether or not you want to take advantage of these functions.
You can convert the format of EXITxx to PROGxx using the IEFEXPR REXX exec provided by IBM. For example, the following statement in EXITxx
EXIT EXITNAME(xx)MODNAME(yy)
would look like this in PROGxx:
EXIT ADD EXITNAME(xx) MODNAME(yy)
For information about how to use the IEFEXPR REXX exec to convert the exit definitions in EXITxx to equivalent definitions in PROGxx, see IEAAPFxx (authorized program facility list).

For information about how to use PROGxx to define and control the use of exits, see PROG.