Installing and Configuring Samba on Ubuntu: File Sharing with Windows – ITFROMZERO

I first started using Samba when managing a small office — 15 Windows machines and 2 Ubuntu Servers acting as file servers. Back then I thought it was straightforward, just sharing a folder. But after 6 months in production, I realized there’s quite a lot to pay attention to if you want Samba to be both stable and secure.

Table of Contents

Background and Why You Need Samba

At its core, Samba implements the SMB/CIFS protocol on Linux — the same protocol Windows uses for network file sharing. This means an Ubuntu server can communicate directly with Windows machines without requiring any additional software on the client side.

My specific use case: a Windows-based dev team wanted direct access to the code directory on the Ubuntu server — no SSH, no manual file copying. Samba solved this cleanly.

Some common use cases:

Internal file server for Windows-based offices
Folder sharing between a Linux VM and Windows host (VMware, VirtualBox)
Self-hosted NAS replacing Synology/QNAP
Backup destination from Windows machines over the network

Installing Samba on Ubuntu

I’ve tested this and run it on Ubuntu 22.04 LTS. Installation is fast with no complex dependencies:

sudo apt update
sudo apt install samba samba-common-bin -y

Check the version and service status:

smbd --version
sudo systemctl status smbd

If the service isn’t running, start and enable it to auto-start on boot:

sudo systemctl start smbd nmbd
sudo systemctl enable smbd nmbd

nmbd is the NetBIOS Name Service — it lets Windows machines find the server by hostname instead of needing to remember the IP. If you’re managing your own internal name resolution, pairing this with a local DNS server like Bind9 gives you much cleaner hostname control across the network. Skipping nmbd still allows IP-based connections, but the server won’t appear in Network Neighborhood.

Detailed Samba Configuration

The main configuration file is at /etc/samba/smb.conf. Before making changes, back it up — a habit I picked up after the first time I broke the config and spent an entire afternoon restoring it:

sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.backup

Configuring the [global] Section

The [global] section contains settings that apply to the entire server — workgroup, security mode, logging, and some performance tweaks. Open the file to edit:

sudo nano /etc/samba/smb.conf

[global]
   workgroup = WORKGROUP
   server string = Ubuntu File Server
   security = user
   map to guest = bad user
   dns proxy = no

   # Log settings
   log file = /var/log/samba/log.%m
   max log size = 1000
   logging = file

   # Performance tuning
   socket options = TCP_NODELAY IPTOS_LOWDELAY
   read raw = yes
   write raw = yes
   max xmit = 65535

One commonly overlooked point: workgroup = WORKGROUP must match the workgroup on your Windows machines. Quick check on Windows: right-click This PC → Properties → Advanced system settings → Computer Name.

Creating Shared Folders

Real-world example: I create 2 shares — a public share for the whole team to read and write, and a private share for admins only:

# Create directories
sudo mkdir -p /srv/samba/public
sudo mkdir -p /srv/samba/private

# Permissions for public folder
sudo chown -R nobody:nogroup /srv/samba/public
sudo chmod -R 0775 /srv/samba/public

# Permissions for private folder
sudo chown -R root:root /srv/samba/private
sudo chmod -R 0770 /srv/samba/private

Add the following to the end of smb.conf:

[Public]
   comment = Public Share - Team Access
   path = /srv/samba/public
   browsable = yes
   writable = yes
   guest ok = yes
   read only = no
   create mask = 0664
   directory mask = 0775

[Private]
   comment = Private - Admin Only
   path = /srv/samba/private
   browsable = yes
   writable = yes
   guest ok = no
   valid users = sambaadmin
   create mask = 0660
   directory mask = 0770

Creating a Samba User

Samba uses its own user database — it doesn’t use /etc/passwd directly. The user must exist in the Linux system first, then be added to Samba:

# Create system user (no login shell needed)
sudo useradd -M -s /usr/sbin/nologin sambaadmin

# Add to Samba database and set password
sudo smbpasswd -a sambaadmin

# Enable user
sudo smbpasswd -e sambaadmin

Small note: CentOS/RHEL typically uses /sbin/nologin, while Ubuntu uses /usr/sbin/nologin. On modern Ubuntu both work because /sbin is a symlink to /usr/sbin — but stick with /usr/sbin/nologin for consistency.

Configuring the Firewall

Opening ports for Samba takes just one command:

sudo ufw allow samba
sudo ufw status

ufw allow samba automatically opens ports 137, 138 (UDP) and 139, 445 (TCP). In a production environment, it’s much safer to restrict this to your internal subnet only — especially since open SMB ports are a frequent attack vector (see this guide on detecting and responding to a hacked server for what that exposure can lead to):

sudo ufw allow from 192.168.1.0/24 to any app samba

Testing and Monitoring

Validate Config Before Restarting

Always check the syntax before restarting the service — a bad config will prevent smbd from starting, taking all shares down immediately:

testparm

Once you see Loaded services file OK, it’s safe to restart:

sudo systemctl restart smbd nmbd

Testing the Connection Locally

# List all shares
smbclient -L localhost -U sambaadmin

# Connect to the Private share
smbclient //localhost/Private -U sambaadmin

# Connect anonymously to the Public share
smbclient //localhost/Public -N

Monitoring Active Connections

smbstatus is the command I reach for most when troubleshooting — it shows who’s connected, which files are locked, and from which IP. Super handy when someone reports they can’t open a file: 9 times out of 10 it’s because someone else has it locked. For deeper visibility into which ports are actually listening and what connections are established on the server side, ss is a faster and more capable alternative to netstat worth having in your toolkit.

# View sessions and open files
smbstatus

# More detail
smbstatus --verbose

# Watch log realtime
sudo tail -f /var/log/samba/log.smbd

Common Errors

NT_STATUS_LOGON_FAILURE: The user exists in Linux but hasn’t been added to the Samba database. Run sudo smbpasswd -a username.

NT_STATUS_ACCESS_DENIED: Directory permissions are incorrect. Double-check that chown and chmod align with valid users in smb.conf.

Server not visible in Network Neighborhood: nmbd isn’t running or has crashed. Run sudo systemctl status nmbd and restart if needed.

Connecting from Windows

Open File Explorer and type in the address bar:

\\192.168.1.100\Public

Replace 192.168.1.100 with your Ubuntu server’s IP. Mapping as a drive letter is much more convenient — especially for users unfamiliar with UNC paths:

# Run on Windows (Command Prompt or PowerShell)
net use Z: \\192.168.1.100\Public /persistent:yes

# With authentication
net use Z: \\192.168.1.100\Private /user:sambaadmin /persistent:yes

After 6 months running with around 20 simultaneous Windows connections, Samba on Ubuntu 22.04 has been remarkably stable. The memory footprint was lower than I expected — smbd + nmbd only consume around 50–80MB RAM. The only downside: nmbd occasionally needs a manual restart when the network interface changes, but that’s only come up once every few months.