How to Build a Secure and High-Performance File Server on Ubuntu: Samba & NFS Setup Guide

1. What Are the Benefits of Building a File Server on Ubuntu?

What Is a File Server?

A file server is a server that allows multiple devices on a network to store and share common files. It streamlines file exchange within home or office networks, enables centralized data management, simplifies backups, and offers many additional advantages.

For example, if multiple people need to edit the same document, saving it on a file server allows everyone to access the latest version, rather than exchanging files saved on local PCs. It also reduces the risk of storing important data on individual machines and serves as an effective safeguard against data loss.

Why Choose Ubuntu?

Many operating systems can be used to build a file server, but Ubuntu is one of the most popular choices for the following reasons:

1. Free to Use

Ubuntu is an open-source Linux distribution, meaning it requires no licensing fees. This makes it a highly attractive option for individuals or organizations wanting to build a server environment while keeping costs low.

2. Lightweight and Highly Stable

Ubuntu consumes few system resources and can run on older PCs or devices like Raspberry Pi. Choosing an LTS (Long Term Support) version provides long-term security updates and bug fixes, making it ideal for server use.

3. Rich Support for Tools Like Samba and NFS

Ubuntu makes it easy to install and configure network file systems such as Samba (for Windows file sharing) and NFS (for Linux/Unix file sharing). With abundant packages and documentation, even beginners can build a server with confidence.

4. Large Community and Extensive Documentation

Because Ubuntu is widely used around the world, you can easily find solutions online when issues arise. Extensive documentation in English and other languages makes the platform friendly even for users who are not comfortable with English.

Perfect for Home or Small Office Environments

A file server built with Ubuntu is ideal for sharing data across multiple devices in a home network or for collaborative work in a SOHO environment. Compared to purchasing a dedicated NAS device, Ubuntu lets you create a more flexible and cost-effective solution tailored to your needs.

Here are some example use cases:

• A media server for sharing photos and videos across the household
• Sharing invoices, quotes, and documents in a small business
• Exchanging code and documentation within a development team

2. Comparing File-Sharing Methods: Differences Between Samba and NFS

When building a file server on Ubuntu, the two primary options are Samba and NFS. Both allow file sharing over a network, but they differ in supported client OS and functional characteristics. This section compares the features of each method to help you decide which one fits your environment.

What Is Samba? — Excellent Compatibility With Windows

Samba implements the Windows file-sharing protocol SMB (Server Message Block) on Linux. Installing Samba on Ubuntu allows you to create a file server that Windows PCs can access just like a network drive.

Features of Samba

• Excellent compatibility with Windows
• Easy access to shared folders via Windows Explorer
• Granular configuration of user authentication and permissions
• GUI-based configuration tools (e.g., Webmin) are available

When Samba Is the Best Choice

• When sharing files with Windows clients
• When sharing files between different OS platforms (e.g., Windows + Linux)
• When a user-friendly setup is preferred in home or office scenarios

What Is NFS? — Fast File Sharing for Linux/Unix Systems

NFS (Network File System) is a protocol mainly used for file sharing between Linux and Unix systems. From the client’s perspective, an NFS server’s folder behaves almost like a local directory.

Features of NFS

• Ideal for Linux-to-Linux file sharing
• Lightweight and high-speed performance
• Simple configuration suitable for large-scale sharing
• Requires careful security configuration (IP-based access control)

When NFS Is the Best Choice

• Linux-based server environments
• Shared server directories for development teams
• Scenarios requiring lightweight and high-speed file transfers

Comparison Table: Samba vs. NFS

Which Should You Choose?

Ultimately, the choice depends on client OS, use case, and priorities:

• Samba is best when sharing with Windows clients
• NFS is best for Linux-to-Linux high-speed sharing
• For mixed environments, using both Samba and NFS is also a valid approach

Ubuntu’s flexibility allows you to combine both based on your needs.

3. [Samba] How to Build a File Server on Ubuntu

In this section, we explain how to install and configure Samba on Ubuntu to build a file server. This method is especially effective when sharing files with Windows clients.

Preparation: Update Ubuntu and Check Installed Packages

First, update your Ubuntu system to the latest version. Open a terminal and run the following commands:

sudo apt update
sudo apt upgrade

Next, check whether Samba is already installed:

smbclient --version

If no version is shown, install Samba in the next step.

How to Install Samba

Install the Samba package using the following command:

sudo apt install samba -y

After installation, verify that the service is active:

sudo systemctl status smbd

If it displays “active (running)”, Samba is running correctly.

Configuring smb.conf and Creating a Shared Folder

The Samba configuration file is located at /etc/samba/smb.conf. First, create a shared directory. In this example, we use /srv/samba/shared as the shared folder.

sudo mkdir -p /srv/samba/shared
sudo chmod 777 /srv/samba/shared

Next, edit the configuration file:

sudo nano /etc/samba/smb.conf

Add the following configuration at the end of the file:

[Shared]
   path = /srv/samba/shared
   browseable = yes
   read only = no
   guest ok = yes

This configuration creates a public folder writable by anyone. For secure use, configure user authentication as described later.

Apply the settings by restarting Samba:

sudo systemctl restart smbd

Creating Samba Users and Setting Access Permissions

To enhance security, it is recommended to create Samba users and restrict access.

1. Create a local Ubuntu user (skip if it already exists):

sudo adduser sambauser

2. Register the user as a Samba account:

sudo smbpasswd -a sambauser

3. Change the directory ownership and restrict access:

sudo chown sambauser:sambauser /srv/samba/shared
sudo chmod 770 /srv/samba/shared

4. Modify smb.conf to require authentication:

[SecureShared]
   path = /srv/samba/shared
   browseable = yes
   read only = no
   valid users = sambauser

How to Connect From a Windows Client

Once Samba is set up, you can connect from a Windows PC using these steps:

1. Open File Explorer
2. Enter the following in the address bar: \\<Ubuntu-server-IP>\Shared
3. When prompted, enter the username and password for sambauser

If successful, the shared folder will function just like a regular directory on Windows.

4. [NFS] How to Build a File Server on Ubuntu

NFS (Network File System) is a lightweight and fast network file-sharing protocol widely used in Linux and Unix environments. It is easy to install on Ubuntu and enables smooth file exchange between multiple Linux machines.

Here, we walk through the steps to set up an NFS server on Ubuntu.

How to Install the NFS Server

Install the NFS server package by running the following commands on the Ubuntu server:

sudo apt update
sudo apt install nfs-kernel-server -y

Verify that the service is running:

sudo systemctl status nfs-server

If it shows “active (running)”, the installation was successful.

Configuring /etc/exports and Defining Shared Directories

Next, create a directory you want clients to access. In this example, we use /srv/nfs/shared:

sudo mkdir -p /srv/nfs/shared
sudo chown nobody:nogroup /srv/nfs/shared
sudo chmod 755 /srv/nfs/shared

Edit the NFS configuration file:

sudo nano /etc/exports

Add the following line (replace 192.168.1.0/24 with your network):

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

Apply the settings:

sudo exportfs -a
sudo systemctl restart nfs-server

NFS server setup is now complete.

How to Mount From a Linux Client

On each Linux client that will access the NFS server, install the NFS client package:

sudo apt update
sudo apt install nfs-common -y

Create a mount point such as /mnt/nfs_shared:

sudo mkdir -p /mnt/nfs_shared

Then mount the NFS share:

sudo mount -t nfs 192.168.1.10:/srv/nfs/shared /mnt/nfs_shared

※ Replace 192.168.1.10 with your NFS server’s IP address.

Once mounted, the shared directory behaves like a local folder.

Auto-Mount on Boot (Optional)

To mount the NFS share automatically on startup, add this line to /etc/fstab:

192.168.1.10:/srv/nfs/shared /mnt/nfs_shared nfs defaults 0 0

This ensures the NFS share mounts automatically at boot.

NFS-Specific Access Restrictions and Important Notes

NFS uses IP-based access control, unlike Samba. In /etc/exports, always specify only trusted networks or hosts.

Additionally, if the UID (User ID) and GID (Group ID) on the server and client do not match, file ownership may not be interpreted correctly. For smooth operation, it is advisable to use matching UIDs and GIDs across systems.

With this, your Ubuntu NFS file server is ready. Compared to Samba, NFS is simpler and faster, making it highly suitable for Linux environments.

5. Security and Operational Best Practices

While a file server is a powerful tool for sharing data over a network, it also increases the risk of data leaks and unauthorized access if proper security measures are not implemented. This section introduces essential security and management best practices for running an Ubuntu file server safely and efficiently.

Restrict Access With the Firewall (ufw)

Ubuntu includes a built-in firewall called ufw (Uncomplicated Firewall). For Samba- or NFS-based file sharing, you can limit unnecessary network traffic by explicitly allowing only the required ports.

Example: Allowing Ports for Samba

sudo ufw allow Samba

This command opens all ports required for Samba (137, 138, 139, 445) at once.

Example: Allowing Ports for NFS

NFS ports vary depending on the environment, so you may need to open them individually or configure them to use fixed ports.

sudo ufw allow from 192.168.1.0/24 to any port nfs

※ 192.168.1.0/24 represents the allowed network range.

Strengthen Access Control and User Authentication

Samba Access Restrictions

• Use valid users to restrict who can access each share
• Use read only = yes to allow read-only access when needed
• Use hosts allow and hosts deny for IP-based restrictions

Example (smb.conf):

[SecureShared]
   path = /srv/samba/secure
   read only = no
   valid users = user1
   hosts allow = 192.168.1.

NFS Access Restrictions

• Specify allowed IP addresses or networks in /etc/exports
• Explicitly define rw (read/write) or ro (read-only)
• Use root_squash to prevent clients from using root privileges

Example:

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

Monitor Logs and Detect Irregularities

Monitoring logs is essential for detecting unauthorized access, errors, or suspicious activity.

• Samba logs: /var/log/samba/log.smbd
• NFS logs: /var/log/syslog or journalctl -u nfs-server

Using tools like fail2ban allows you to automatically block IP addresses after repeated login failures.

Build an Automated Backup System

Regular backups are essential to protect against accidental deletion, corruption, or hardware failure.

Backup Examples

• Differential backup using rsync
• Scheduled backups using cron
• Storing backups on external HDDs or NAS
• Syncing with cloud storage (Google Drive, Dropbox) using rclone

Example: A cron job that backs up daily at 2:00 AM

0 2 * * * rsync -a /srv/samba/shared/ /mnt/backup/shared/

Keep Software Updated Regularly

Regular updates are one of the most effective ways to prevent security vulnerabilities.

sudo apt update && sudo apt upgrade -y

Using an LTS version of Ubuntu ensures long-term access to security updates and stability.

Running a file server is not a one-time setup. For stable operation, you must consistently manage security, backups, and maintenance.

6. Common Issues and How to Fix Them (Troubleshooting)

Even after setup, file servers may experience configuration issues or operational problems. This section summarizes common issues with Samba and NFS file servers on Ubuntu and how to resolve them.

Cannot Connect / Shared Folder Not Visible

Symptoms

• Windows or Linux clients cannot access shared folders
• The server does not appear in the network list

Main Causes and Solutions

Permission Errors

Symptoms

• Cannot create or modify files
• “Access denied” messages appear

Main Causes and Solutions

Mount Not Persisting / Shared Folder Disappears After Reboot

Symptoms

• NFS-mounted shared folders disappear after the client reboots
• The mount command needs to be run manually each time

Main Causes and Solutions

Example fstab entry (for NFS):

192.168.1.10:/srv/nfs/shared /mnt/nfs_shared nfs defaults,_netdev,nofail 0 0

Files Not Visible / Changes Not Synced

Symptoms

• Files saved from another client do not appear immediately
• Changes take time to reflect across devices

Main Causes and Solutions

Checking Logs for Diagnosis

When investigating issues on Ubuntu, checking log files is essential.

Samba Logs

cat /var/log/samba/log.smbd

NFS Logs

journalctl -u nfs-server

Logs contain information about failed access attempts, authentication errors, and configuration issues. Searching error messages online usually leads you to relevant solutions.

Tips for Effective Troubleshooting

• Change settings in small steps and test each change
• Always back up configuration files
• Use validation tools such as testparm and exportfs -v
• Restart services or reload configuration after making changes

7. FAQ: Frequently Asked Questions About Ubuntu File Servers

This section covers common questions and concerns beginners and intermediate users encounter when building and operating Ubuntu file servers.

Q1. Should I use Samba or NFS?

A. Choose based on the client operating system.

• Samba (SMB) for Windows environments
  Easy access through File Explorer
• NFS for Linux-to-Linux sharing
  Lightweight, fast, and stable

You can also use both in mixed environments—there is no need to limit yourself to only one.

Q2. How do I share an external storage device (USB HDD)?

A. Mount the external storage device first, then configure Samba or NFS to share the mounted directory.

1. Check available devices:

lsblk

2. Create a mount point and mount the device:

sudo mkdir /mnt/usb
sudo mount /dev/sdX1 /mnt/usb

3. Then configure Samba or NFS to share /mnt/usb.

If you want it to mount automatically, add an entry in /etc/fstab.

Q3. I cannot connect to Samba from Windows 11.

A. The issue may be related to SMB protocol versions or authentication.

Try adding the following to /etc/samba/smb.conf:

client min protocol = SMB2
server min protocol = SMB2

• Avoid guest access—use username/password instead
• If SMB 1.0 is enabled on Windows, consider disabling it for security reasons

Q4. How should I back up my file server?

A. Automating backups is the most reliable approach.

• Differential backups using rsync
• Scheduled tasks using cron
• Backup to external HDD or NAS
• Sync with cloud services using rclone

Example crontab job (runs daily at 2 AM):

0 2 * * * rsync -a /srv/samba/shared/ /mnt/backup/

Q5. Which is better for a file server: Ubuntu Desktop or Ubuntu Server?

A. Ubuntu Server for stable long-term operation; Ubuntu Desktop for ease of use.

If you do not need a GUI, Ubuntu Server tends to be more secure and resource-efficient.

8. Summary: Build a Flexible File-Sharing System With Ubuntu

Building a file server on Ubuntu is an excellent choice for creating a cost-efficient, stable, and customizable file-sharing environment. This guide covered the differences between Samba and NFS, step-by-step setup instructions, security practices, troubleshooting methods, and more.

Choose Samba or NFS Based on Your Use Case

Select the file-sharing method according to your needs:

• Samba for Windows file sharing — direct access from File Explorer
• NFS for Linux-to-Linux high-speed sharing — lightweight and efficient

You can also combine both for mixed environments.

Focus on Security and Maintainability

• Configure firewalls and access restrictions
• Maintain system health with regular updates and log monitoring
• Implement automated backups to prepare for failures

Why Build a Custom File Server?

While purchasing a NAS is an option, creating your own server with Ubuntu provides:

• A simple system with only the features you need
• Flexibility in hardware and storage capacity
• Valuable skills for both personal learning and business applications

If the process seemed difficult at first, we hope this guide helped demonstrate that building your own file server is entirely within reach.

Ubuntu allows you to create a powerful and versatile file server environment suitable for everything from home use to professional applications. Choose the setup that best fits your network and workflow.