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NFS Administration Guide

WebNFS Administration Tasks

This section provides instructions for administering the WebNFS system. The following tasks are discussed.

Planning for WebNFS Access

To use the WebNFS functionality, you first need an application capable of running and loading an NFS URL (for example, nfs://server/path). The next step is to choose the file system that will be exported for WebNFS access. If the application is web browsing, often the document root for the web server is used. Several factors need to be considered when choosing a file system to export for WebNFS access.

  1. Each server has one public file handle that by default is associated with the server's root file system. The path in an NFS URL is evaluated relative to the directory with which the public file handle is associated. If the path leads to a file or directory within an exported file system, then the server provides access. You can use the -public option of the share command to associate the public file handle with a specific exported directory. Using this option allows URLs to be relative to the shared file system rather than to the servers' root file system. By default the public file handle points to the root file system, but this file handle does not allow web access unless the root file system is shared.

  2. The WebNFS environment allows users who already have mount privileges to access files through a browser regardless of whether the file system is exported using the -public option. Because users already have access to these files through the NFS setup, this should not create any additional security risk. You only need to share a file system using the -public option if users who cannot mount the file system need to use WebNFS access.

  3. File systems that are already open to the public make good candidates for using the -public option, like the top directory in an ftp archive or the main URL directory for a web site.

  4. You can use the -index option with the share command to force the loading of an HTML file instead of listing the directory when an NFS URL is accessed.

    After a file system is chosen, review the files and set access permissions to restrict viewing of files or directories as needed. Establish the permissions as appropriate for any NFS file system that is being shared. For many sites, 755 permissions for directories and 644 permissions for files provides the correct level of access.

    Additional factors need to be considered if both NFS and HTTP URLs are going to be used to access one Web site. These are described in "WebNFS Limitations With Web Browser Use".

How to Enable WebNFS Access

Starting with the 2.6 release, by default all file systems that are available for NFS mounting are automatically available for WebNFS access. The only time that this procedure needs to be followed is on servers that do not already allow NFS mounting, if resetting the public file handle is useful to shorten NFS URLs, or if the -index option is required.

  1. Edit the /etc/dfs/dfstab file.

    Add one entry to the file for the file system that you want to have shared automatically. The -index tag is optional.


    share -F nfs -o ro,public,index=index.html /export/ftp

  2. Check that the NFS service is running on the server.

    If this is the first share command or set of share commands that you have initiated, it is likely that the NFS daemons are not running. The following commands kill and restart the daemons.


    # /etc/init.d/nfs.server stop
# /etc/init.d/nfs.server start

  3. Share the file system.

    After the entry is in /etc/dfs/dfstab, the file system can be shared by either rebooting the system or by using the shareall command. If the NFS daemons were restarted in step 2, then this command does not need to be run because the script runs the command.


    # shareall

  4. Verify that the information is correct.

    Run the share command to check that the correct options are listed:


    # share
-        /export/share/man   ro   ""
-        /usr/src     rw=eng   ""
-        /export/ftp    ro,public,index=index.html  ""

How to Browse Using an NFS URL

Browsers capable of supporting WebNFS access should provide access using an NFS URL that looks something like:


nfs://server<:port>/path

server is the name of the file server, port is the port number to use (the default value is 2049), and path is the path to the file. Path can either be relative to the public file handle or relative to the root file system on the server.

Note -

In most browsers, the URL service type (for example, nfs or http) is remembered from one transaction to the next, unless a URL that includes a different service type is loaded. When using NFS URLs, if a reference to an HTTP URL is loaded, then subsequent pages are loaded using the HTTP protocol instead of the NFS protocol, unless the URLs specify an NFS URL.

How to Enable WebNFS Access Through a Firewall

You can enable WebNFS access for clients that are not part of the local subnet by configuring the firewall to allow a TCP connection on port 2049. Just allowing access for httpd does not allow NFS URLs to be used.