You create an automount policy that specifies directories containing only mount points, which is the recommended method of managing file systems. An automount policy specifies the file systems that are to be mounted by the automount facility. As each mount point is accessed, an appropriate file system is mounted. The mount point directories are created as they are required. If the file system is no longer used, the mount point directories are deleted.

Think of the automount facility as an administrator that has total control over a directory. When a name is accessed in this directory, the automount facility checks the automount policy for the file system that is supposed to be associated with that name. Then it performs a mkdir followed by a mount and moves out of the way. Now the root directory of that newly mounted file system can be accessed as that name.

For example, suppose that you had created the USER1 directory with the mkdir command. If you had set up the automount facility and put the automount policy in place, you would not have needed to do that. The USER1 directory would have been dynamically created and the OMVS.USER1 data set automatically mounted at the /u/user1 mount point.

Later, if the /u/user1 file system was not accessed based on certain criteria in your automount policy, the OMVS.USER1 data set is automatically unmounted and the USER1 directory removed.

The automount facility will not manage any directory until it can process the entire policy without encountering any errors.

You can use a prefilter by updating the automount master file to include the name of the filter utility. For more information, see the automount description in z/OS UNIX System Services Command Reference.

The automount file system is mounted with an automove attribute of either AUTOMOVE or UNMOUNT. The automove attribute is set to UNMOUNT only when its parent file system has its automove attribute set to UNMOUNT.

If the automount policy is loaded, you will get a return code of 0. A nonzero return code indicates that the policy was not loaded.