While Time Machine is an excellent backup solution for macOS, external drives aren’t always the most convenient option—especially if (like me) you already have a Linux server with plenty of storage. By configuring Samba on your Linux server, you can use it as a network Time Machine destination, allowing automatic wireless backups without needing to plug in an external drive. Here’s how I set mine up (I used Ubuntu, but have put in commands for other distros as well).

On Linux

1. Install Samba on the Linux Server

# Ubuntu/Debian
sudo apt update
sudo apt install samba avahi-daemon

# RHEL/CentOS/Fedora
sudo dnf install samba avahi

2. Create a Directory for Time Machine Backups

sudo mkdir -p /mnt/timemachine
sudo chown your_username:your_username /mnt/timemachine
sudo chmod 755 /mnt/timemachine

3. Configure Samba

Edit the Samba configuration file:

sudo nano /etc/samba/smb.conf

Add this configuration at the end:

[TimeMachine]
   comment = Time Machine Backup
   path = /mnt/timemachine
   browseable = yes
   writable = yes
   valid users = your_username
   create mask = 0600
   directory mask = 0700
   spotlight = yes
   vfs objects = catia fruit streams_xattr
   fruit:aapl = yes
   fruit:time machine = yes

4. Set Up Samba User Password

sudo smbpasswd -a your_username

5. Restart Samba and Avahi

# Ubuntu/Debian
sudo systemctl restart smbd nmbd avahi-daemon
sudo systemctl enable smbd nmbd avahi-daemon

# RHEL/CentOS/Fedora
sudo systemctl restart smb nmb avahi-daemon
sudo systemctl enable smb nmb avahi-daemon

6. Configure Firewall (if needed)

# Ubuntu/Debian with ufw
sudo ufw allow samba

# RHEL/CentOS/Fedora with firewalld
sudo firewall-cmd --permanent --add-service=samba
sudo firewall-cmd --reload

On the Mac

1. Connect to the Share

Open Finder and press Cmd + K, then enter:

smb://server_ip_or_hostname/TimeMachine

Enter your username and password when prompted.

2. Enable Time Machine to Use Network Drives

If the share doesn’t appear in Time Machine preferences, you may need to enable unsupported volumes:

sudo tmutil setdestination /Volumes/TimeMachine

Or directly set it:

sudo tmutil setdestination smb://username@server_ip/TimeMachine

3. Configure Time Machine

1. Open System Settings → General → Time Machine
2. Click the + button to add a backup disk
3. Select your network share
4. Start the backup

Tips and Considerations

• Space Requirements: Ensure you have enough space on the Linux server (Time Machine typically uses 1-2x your Mac’s storage)
• Performance: Network backups are slower than local ones, especially for the initial backup
• Reliability: Use a wired connection for the first backup if possible
• Size Limits: You can set a quota using Samba or filesystem quotas to prevent Time Machine from using all available space

Optional: Set a Size Limit for Time Machine

On your Mac, create a sparse bundle with a maximum size:

sudo tmutil setdestination /Volumes/TimeMachine
hdiutil create -size 500g -type SPARSEBUNDLE -fs "HFS+J" \
  -volname "Time Machine Backups" \
  ~/Desktop/TimeMachine.sparsebundle

Then move this to your network share and use it as the backup destination.