Starting Share Files with NFS

First, make sure your Linux kernel supports NFS. The status of your system is reflected by proc directory. To look inside the filesystems file, execute the cat command, like this:

tomcat> cat /proc/filesystems
         ext2
nodev    proc
nodev    devpts
         iso9660
nodev    nfs

This file shows you what kind of filesystems you may use with your version of the kernel. If the line nodev nfs is missing, it may mean your NFS filesystem support module is not installed. In this case, try to execute the command modpobe nfs. You must be root to execute it. The output of the command delineates the situation. If module is compiled, the command installs it, and if you repeat the cat command, the clue line will be shown. If your kernel does not support the NFS server, you probably will have to recompile it, but this topic is far beyond the scope of this article.

If you have NFS supported, you can mount files located on the server machine, as we showed in the example. The full format for the mount command is as follows:

mount -t nfs server:exp dir local dir options

Here server is the name of your NFS server, and exp_dir is the full path to the directory to export on the server machine.

Usually this is the end of the story, but to reach maximum productivity for connection via NFS, let's look at options parameters. We will use them later for sure:

The recommended options are intr and hard, and since the latter is the default, intr is enough. With these parameters, we are able to try to increase performance of the NFS connection.

Often we want to do the process of mounting in a hidden way (transparently), perhaps while booting the system. In this case we have to create the corresponding line in the file named /etc/fstab that the system reads while booting. Any line in that file has as a minimum four fields, usually six. Here's an example:

1)device 2)mnt point 3)fs type 4)options
5)dump 6)check order
tiger:/nfs1/home /home nfs rw,hard,intr 0 2

The first parameter describes the device to be mounted. In this example, the NFS server tiger exports /nfs1/home filesystem as the home directory. Field number four points to this filesystem as nfs. The last parameters mean the filesystem should not be dumped and checked in the second order. You can find more details in section five of the man pages. It also is a good idea to start rpc.lockd and rpc.statd. These programs usually initialize from scripts. Once you've done those things, you should have the NFS client running.