The z/OS NFS Server must distinguish between the two different file system types when processing mount requests and other requests that involve the specification of path names: z/OS UNIX file systems and MVS data sets. Prior to z/OS NFS V1R11 this was done via the specification of the special "hfs" prefix for z/OS UNIX file systems and the absence of the prefix for MVS data sets.

As of NFS V1R11, the z/OS NFS file system type management function has been expanded by adding an mvs prefix and a customer configurable path resolution heuristic. The new mvs prefix provides the capability to explicitly specify a prefix for identifying MVS data sets, as the hfs prefix does for z/OS Unix files. The new customer-configurable heuristic enables you to specify how to interpret absolute path names that do not have a prefix specified. By setting the heuristic to indicate that MVS data sets now require a prefix and z/OS Unix files do not, symbolic links in z/OS Unix mount paths can be supported.