For multivolume data sets, request volume affinity if you request
unit affinity. Code:
//ddname DD UNIT=AFF=ddname,VOLUME=REF=*.ddname,...
If you code only volume affinity for a multivolume data set, the
following can happen:
- The system assigns the requested volumes and allocates them to
a device. Thus, the device is to be shared by all the DD statements
requesting volume affinity.
- The system asks the operator to mount the first volume for the
referenced DD statement on the allocated device.
- At the end of the first volume, the system asks the operator to
demount the first volume and mount the second volume.
- If the data set is reopened, the system asks the operator to remount
the first volume on a device not used for the volume affinity request.
- When the system processes the referring DD statement, it asks
the operator to mount the first volume on the device assigned to the
volume affinity request. The job now enters a wait because the system
has requested the first volume on two different devices.