Automatic File-System Sharing

Servers provide access to their file systems by sharing them over the NFS environment. You specify which file systems are to be shared with the share command and/or the /etc/dfs/dfstab file.

Entries in the /etc/dfs/dfstab file are shared automatically whenever you start NFS server operation. You should set up automatic sharing if you need to share the same set of file systems on a regular basis. For example, if your computer is a server that supports diskless clients, you need to make your clients' root directories available at all times. Most file system sharing should be done automatically, the only time that manual sharing should occur is during testing or troubleshooting.

The dfstab file lists all the file systems that your server shares with its clients and controls which clients can mount a file system. If you want to modify dfstab to add or delete a file system or to modify the way sharing is done, edit the file with any supported text editor (such as vi). The next time the computer enters run level 3, the system reads the updated dfstab to determine which file systems should be shared automatically.

Each line in the dfstab file consists of a share command--the same command you type at the command-line prompt to share the file system. The share command is located in /usr/sbin.

How to Set Up Automatic File-System Sharing

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

   Add one entry to the file for each file system that you want to be automatically shared. Each entry must be on a line by itself in the file and uses this syntax:

   share [-F nfs] [-o specific-options] [-d description] pathname

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 the daemons and restart them.

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

   This ensures that NFS service is now running on the servers and will restart automatically when the server is at run level 3 during boot.

   At this point, set up your autofs maps so that clients can access the file systems you have shared on the server. See "Setting Up Autofs".