How is the PDSMENQ resource used?
PDSMENQ is documented as an ENQUEUE/RESERVE with a requirement that it be converted into a global enqueue.
A RESERVE limits access, to an entire DASD volume, to a single z/OS, using hardware functionality.
Using a RESERVE is safe but affects performance.
With GRS, the RESERVE can be turned into a software facility which in turn, allows other z/OS images to access other parts of the volume.
PDSMENQ is an enqueue unique to PDSMAN. It is similar to ISPF's SPFEDIT enqueue, which is also normally converted to a global enqueue.
The only way to avoid the PDSMENQ RESERVE, is to not use PDSMAN rules (such as $ACCESS REF=Y or $UPDATE ) or functions that need to serialize access to PDS data.
Information regarding PDSMENQ can be found in the PDSMAN Installation Guide - Chapter 4: Customizing the Runtime Environment 4–3