How to Set Up Ubuntu Network File System (NFS) Server and Client

How to Set Up Ubuntu Network File System (NFS)

Network File System (NFS) is a network filesystem protocol that allows one Linux system to share directories with other systems over a network. On Ubuntu, an NFS server exports a directory, while an NFS client mounts that export into its local filesystem.

This makes NFS useful for centralized storage, Linux home directories, application data, virtualization environments, development labs, backup repositories and shared files between Ubuntu servers.

In this tutorial, we will build a complete Ubuntu NFS environment using one Ubuntu server and one Ubuntu client. The example configuration uses a private network and restricts access to the client subnet rather than exposing the share to every host.

What Is Ubuntu Network File System?

Ubuntu Network File System refers to using NFS on Ubuntu systems to provide network-based filesystem access. The server makes a directory available through an NFS export, and the client mounts that export at a local directory.

After mounting, applications on the client can normally access the remote directory using standard filesystem operations such as reading, writing, creating and deleting files, subject to the permissions configured on both systems.

Ubuntu NFS Server and Client Architecture

The basic NFS architecture is simple: the server owns the physical data and exports a directory, while the client connects to that export and mounts it locally.

In this example, the server address is 192.168.1.10 and the client address is 192.168.1.20. These are examples; replace them with the addresses used in your own environment.

Requirements and Lab Setup

Before configuring NFS, prepare two Ubuntu systems that can communicate with each other over the network.

Step 1: Install the NFS Server on Ubuntu

sudo apt update

sudo apt install nfs-kernel-server

sudo systemctl status nfs-server

sudo systemctl start nfs-server

Step 2: Create the NFS Shared Directory

The directory exported by NFS can reside on a local disk, RAID array, storage volume or another filesystem mounted on the Ubuntu server.

For this tutorial, we will use /srv/nfs.

sudo mkdir -p /srv/nfs

Create a test file so that you can verify access from the client:

echo "Hello from Ubuntu NFS Server" | sudo tee /srv/nfs/test.txt

Step 3: Configure /etc/exports

The /etc/exports file defines the directories exported by the NFS server and the clients or networks allowed to access them.

Open the file:

sudo nano /etc/exports

Add an entry similar to the following:

/srv/nfs 192.168.1.0/24(rw,sync,no_subtree_check)

In this example, clients on the 192.168.1.0/24 network are allowed read/write access.

Understanding the NFS Export Options

Step 4: Apply and Verify NFS Exports

After modifying /etc/exports, reload the export configuration with:

sudo exportfs -ra

The -r option re-exports directories, while -a applies the operation to all exports.

Verify the active exports:

sudo exportfs -v

You should see the exported directory together with the configured client restrictions and options.

Step 5: Configure the Ubuntu Firewall for NFS

If a firewall is active on the NFS server, allow NFS traffic from the client network rather than opening the service broadly to untrusted networks.

For an NFSv4-focused deployment, TCP port 2049 is the important NFS service port. Ubuntu’s documentation also notes that NFS-related services and configuration can vary depending on the Ubuntu release and NFS setup.

With UFW, an example restricted rule is:

sudo ufw allow from 192.168.1.0/24 to any port 2049 proto tcp

Check the resulting firewall configuration:

sudo ufw status

Step 6: Install the NFS Client on Ubuntu

Move to the Ubuntu client machine and install nfs-common.

sudo apt update
sudo apt install nfs-common

The package provides the client-side NFS utilities required to mount network filesystems.

Step 7: Mount the Ubuntu NFS Share

Create a mount point on the client:

sudo mkdir -p /mnt/nfs

Mount the server’s exported directory:

sudo mount 192.168.1.10:/srv/nfs /mnt/nfs

Verify the mounted filesystem:

df -h /mnt/nfs

Then list its contents:

ls -la /mnt/nfs

You should see the test.txt file created earlier on the server.

Test Write Access

If the export and filesystem permissions allow writing, test the connection from the client:

echo "Created from NFS client" | sudo tee /mnt/nfs/client-test.txt

Check the server’s /srv/nfs directory to confirm the file has been created.

Step 8: Make the NFS Mount Persistent with /etc/fstab

A manually mounted NFS filesystem normally needs to be mounted again after a reboot. You can configure a persistent mount through /etc/fstab.

Open the client configuration:

sudo nano /etc/fstab

Add:

192.168.1.10:/srv/nfs /mnt/nfs nfs defaults,_netdev 0 0

Why Use _netdev?

The _netdev option identifies the filesystem as network-dependent. This helps the system treat the mount as dependent on network availability.

After editing /etc/fstab, reload systemd’s configuration:

sudo systemctl daemon-reload

Test the configuration without rebooting:

sudo umount /mnt/nfs
sudo mount -a
df -h /mnt/nfs

Understanding Ubuntu NFS Permissions

One of the most common sources of confusion with NFS is the difference between an NFS export permission and the Linux filesystem permission.

An export can permit a client to access a directory with read/write privileges, but the underlying Unix ownership and mode bits still affect what users can actually do.

Ubuntu NFS Security Best Practices

NFS should normally be deployed on a trusted network or protected network segment. Do not treat NFS as an Internet-facing file-sharing protocol.

• Restrict exports to specific clients or trusted subnets.
• Use a firewall to limit NFS traffic.
• Avoid exporting sensitive system directories.
• Keep normal Linux filesystem permissions enabled.
• Use root_squash rather than disabling root squashing without a specific reason.
• Use stable DNS names or static/reserved IP addresses for infrastructure systems.
• Keep Ubuntu and NFS packages updated.
• For environments requiring stronger authentication or encrypted NFS traffic, evaluate NFS with Kerberos.

Ubuntu’s current server documentation describes Kerberos-backed NFS configurations using security modes such as krb5, krb5i and krb5p, with krb5p providing authentication, integrity and privacy protection.

Troubleshooting Ubuntu NFS

1. Permission Denied

If the client receives a permission error, check both the export and the filesystem permissions.

sudo exportfs -v
ls -ld /srv/nfs

Confirm that the client’s address is allowed by /etc/exports and reapply the export:

sudo exportfs -ra

2. NFS Mount Hangs or Times Out

First test basic network connectivity:

ping 192.168.1.10

Then verify that the NFS service is running on the server:

sudo systemctl status nfs-server

Also check firewall rules and confirm that TCP port 2049 is reachable from the client when using the NFSv4 workflow described here.

3. The Export Does Not Appear

On the server, inspect the active exports:

sudo exportfs -v

Re-read the export configuration:

sudo exportfs -ra

4. Mount Point Problems

Make sure the client mount directory exists and is not being used as a location for important local files.

sudo mkdir -p /mnt/nfs
ls -la /mnt/nfs

5. fstab Mount Fails After Reboot

Test the entry manually:

sudo umount /mnt/nfs
sudo mount -a

If the command returns an error, correct the /etc/fstab entry before rebooting.

Useful Ubuntu NFS Diagnostic Commands

Build an Ubuntu and Linux Infrastructure Knowledge Cluster

This NFS tutorial can serve as part of a broader VMoreCloud Ubuntu and Linux infrastructure topic cluster. Continue with related storage, networking, firewall and Ubuntu Server guides.

Ubuntu NFS Deployment Best Practices

Conclusion

Setting up an Ubuntu Network File System (NFS) provides a straightforward way to centralize shared Linux storage and make it available to authorized systems across a network.

The basic workflow is:

1. Install nfs-kernel-server on the Ubuntu server.
2. Create the directory that will be shared.
3. Define authorized clients in /etc/exports.
4. Apply the configuration with exportfs.
5. Install nfs-common on the client.
6. Create a client-side mount point.
7. Mount the NFS export.
8. Use /etc/fstab for persistent mounts.
9. Restrict access with firewall and export rules.

For a small Linux lab, this setup can provide a useful centralized storage layer. In larger environments, combine NFS with appropriate storage architecture, identity management, monitoring, backups and security controls.