Introduction

The Network File System (NFS) is a distributed file system protocol that allows a client system to access files over a network as if they were stored locally. Developed by Sun Microsystems, NFS is widely used in UNIX, Linux, and similar operating systems to share directories and files between systems seamlessly.

In this guide, we will cover:

  • How NFS works 
  • Setting up an NFS server and client 
  • Configuring firewall rules 
  • Mounting NFS shares manually and persistently

How NFS Works

NFS follows a client-server architecture where:

  1. The NFS Server exports (shares) directories over the network. 
  2. The NFS Client mounts these exported directories to access them. 

Clients can mount these NFS shares:

  • Manually, using the mount command. 
  • Persistently, by configuring the /etc/fstab file to mount the share automatically at boot. 

Setting Up NFS on Linux

We will set up an NFS Server (servera) and an NFS Client (serverb) for file sharing.

Step 1: Update the /etc/hosts File

To ensure both systems recognize each other, update the /etc/hosts file on both the server and client:

vim /etc/hosts

Add the following lines:

192.16.250.10      servera.abc.com

192.16.250.11      serverb.abc.com

Save and exit.

NFS Server Configuration

Step 2: Install the NFS Server Package

On the server (servera), install the required NFS packages:

yum install nfs-utils -y

Step 3: Start and Enable the NFS Service

Enable the NFS service to start on boot and begin running it:

systemctl start nfs-server.service

systemctl enable nfs-server.service

Step 4: Configure the Firewall

Allow NFS service through the firewall:

firewall-cmd –permanent –add-service=nfs

firewall-cmd –reload

Step 5: Create a Directory to Share

Create a directory that will be shared with clients:

mkdir /public

Step 6: Configure the NFS Exports File

Edit the NFS configuration file to define which directories will be shared:

vim /etc/exports

Add the following line:

/public *.abc.com(rw,sync,no_root_squash)

  • rw → Read and write access. 
  • sync → Ensures data is written before a response is sent. 
  • no_root_squash → Allows root users on clients to have root privileges on the share. 

Save and exit.

Step 7: Export the Shared Directory

Apply the changes and export the NFS directory:

exportfs -rv

This makes the directory available for mounting by clients.

NFS Client Configuration

On the client system (serverb), follow these steps to mount and access the shared directory.

Step 1: Install NFS Utilities on the Client

yum install nfs-utils -y

Step 2: Create a Mount Directory

Create a local directory where the NFS share will be mounted:

mkdir /private

Step 3: Mount the NFS Share

Use the mount command to attach the NFS share:

mount -o servera.abc.com:/public /private

Or use the IP address:

mount -o 192.16.250.10:/public /private

Step 4: Verify the Mount

Check if the mount was successful:

df -h

The mounted NFS share should appear in the list.

Persistent Mounting (Auto-Mount at Boot)

To ensure the NFS share is mounted automatically after a reboot, add an entry to the /etc/fstab file.

vim /etc/fstab

Add the following line:

servera.abc.com:/public  /private  nfs  defaults  0  0

Save and exit.

To test the configuration, reboot the client system:

reboot

Once the system restarts, verify the mount using:

df -h

Unmounting the NFS Share

If you need to unmount the NFS share, use:

umount /private

Conclusion

NFS is a powerful and efficient way to share files between Linux systems. By following this guide, you have learned how to:
  1. Set up an NFS server and client
 2. Configure firewall rules for NFS
 3. Export directories on the server
 4. Mount NFS shares manually and persistently
 5. Unmount NFS shares when needed

By implementing NFS in your environment, you can enable seamless file sharing across multiple systems while maintaining control over access and permissions.