How to Automatically Mount an NFS Share on Ubuntu Using systemd

While the traditional method of mounting Network File System (NFS) shares involves editing the /etc/fstab file, this approach can cause boot delays or failures if the network is unavailable during startup. A more robust, modern approach on Ubuntu servers is to use systemd mount units. Systemd allows for delayed, on-demand mounting, ensuring the operating system boots smoothly regardless of network storage availability.

Why Use systemd Over fstab?

Systemd offers granular control over mount dependencies. By using an automount unit, the NFS share is only mounted when a user or application actually attempts to access the directory. This eliminates the dreaded “hanging at boot” issue caused by unreachable network drives.

Step 1: Install NFS Client Packages

First, ensure your Ubuntu system has the necessary NFS client tools installed:

sudo apt update
sudo apt install nfs-common

Step 2: Create the Mount Unit

Systemd requires mount unit files to be named exactly after the mount point path, replacing slashes with dashes. For example, to mount the share at /mnt/nfs_data, the file must be named mnt-nfs_data.mount.

1. Create the mount point directory:

   sudo mkdir -p /mnt/nfs_data

2. Create the systemd mount unit file:

   sudo nano /etc/systemd/system/mnt-nfs_data.mount

3. Add the following configuration, replacing the IP and share path with your NFS server’s details:

   [Unit]
   Description=Mount NFS Share
   After=network-online.target
   Wants=network-online.target
   
   [Mount]
   What=192.168.1.100:/exported/share
   Where=/mnt/nfs_data
   Type=nfs
   Options=rw,soft,timeo=30,retrans=3
   
   [Install]
   WantedBy=multi-user.target

Step 3: Create the Automount Unit

To enable on-demand mounting, create an accompanying automount unit.

1. Create the automount file:

   sudo nano /etc/systemd/system/mnt-nfs_data.automount

2. Add the following configuration:

   [Unit]
   Description=Automount NFS Share
   
   [Automount]
   Where=/mnt/nfs_data
   TimeoutIdleSec=300
   
   [Install]
   WantedBy=multi-user.target

Step 4: Enable and Start the Service

Finally, reload systemd to recognize the new files, then enable and start the automount service (do not enable the .mount service directly):

sudo systemctl daemon-reload
sudo systemctl enable mnt-nfs_data.automount
sudo systemctl start mnt-nfs_data.automount

Now, simply navigate to /mnt/nfs_data. Systemd will detect the access attempt and instantly mount the NFS share in the background, providing a seamless and highly resilient storage solution.