Overview of NFS

Mounting remote resources

When you mount a remote filesystem on a local mount point, you mount the entire filesystem, starting at its root. When you mount a remote resource through NFS, you do not have to mount the entire filesystem. You can mount any directory or file in the filesystem tree and gain access only to that directory or file and anything beneath it, as illustrated in ``Example: mounting a remote resource''.

If you want to mount a single file, you must mount the file on a directory. Once it is mounted, you cannot remove it (using rm) or move it to another directory (using mv); you can only unmount it.

NOTE: When a single file is mounted over NFS, it cannot be opened with the O_CREAT flag. See open(2) for information on O_CREAT.

Example: mounting a remote resource

In the illustration, Machine A is sharing its entire /home filesystem. If Machine B wants access only to the files and subdirectories in /home/brown on Machine A, it can mount just /home/brown, rather than all of /home. Nothing above /home/brown on Machine A will then appear in Machine B's directory tree. Other machines might choose to mount all of /home.

Mounting a Remote Resource

It would be invalid for Machine A to share both /home and /home/brown if both resources reside on the same disk partition. As in the example, it should share only /home and let the network machines to decide whether to mount /home or /home/brown.

© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 22 April 2004