If the data sets specified include partitioned data sets, a second level of hierarchy is shown. This allows you to define one level of directories under the mount point. Thus, you can issue mkdir to create a directory (stored as a PDS or PDSE) and then create files (stored as members of a PDS or PDSE) within that directory.

This use of a PDSE is shown in Figure 1, which illustrates the mapping of file names between client file systems and the MVS file system resulting from a mount command.