SMB automount using systemd

Bazzite
1

Hi - I saw there were repeating questions on how to mount external drives over SMB.

I documented in detail what I did under Bazzite and a bottleneck I had with SELinux. Happy to get feedback on what I could have differently, better, or easier.

Bazzite SMB automount

Make sure that you replace whatever is in “<>” with your own data.

Setup authentication configuration file

Generate a file that defines the login data to mount the volume. The file will be called credentials located at /var/home/<username>/.smb/credentials. Make sure you first generate the folder mkdir /var/home/<username>/.smb.

username=<username>
password=<password>
  • Ensure the credentials file is readable only by the owner: chmod u=rw,go= /var/home/<username>/.smb/credentials
  • Create a mount folder on your local machine: mkdir /var/home/<username>/retrodeck
  • Create a file called var-home-<username>-retrodeck.mount located at /etc/systemd/system. sudo touch /etc/systemd/system/var-home-<username>-retrodeck.mount.

Create mount unit

[Unit]
Description=Mount SMB Retrodeck Share
# A human-readable description of this mount unit.

# Ensures the network is available before trying to mount.
Requires=network-online.target
# This unit will only start if 'network-online.target' is available.
After=network-online.target systemd-resolved.service
# Waits until network and DNS resolution are ready.
Wants=network-online.target systemd-resolved.service
# Suggests that these services should be running, but does not fail if they aren't.

[Mount]
# Defines what to mount and where.

# The network share (SMB/CIFS) that will be mounted.
What=//<yourRemoteServerIP>/<yourRemoteFolder>
# Replace with actual IP and share name, e.g., //192.168.1.100/retrodeck.

# Local mount point where the share will be attached.
Where=/var/home/<username>/retrodeck
# Replace <username> and <retrodeck> with actual values. Make sure that it matches with the folder you create as mount folder.

# Specifies the filesystem type.
Type=cifs
# This is necessary for mounting a Windows SMB/CIFS share.

# Mount options:
Options=rw,uid=1000,gid=1000,nofail,credentials=/var/home/<username>/.smb/credentials,vers=3.0
# `rw`          → Read/write access.
# `uid=1000`    → Ensures that the mounted files are owned by user ID 1000 (your main user).
# `gid=1000`    → Ensures group ownership by group ID 1000.
# `nofail`      → Prevents boot failure if the SMB share is unavailable.
# `credentials=/var/home/<username>/.smb/credentials` → Specifies the file storing the SMB username & password.
# `vers=3.0`    → Forces SMB version 3.0 for security and performance.

# Sets a timeout to stop trying if the mount hangs.
TimeoutSec=30
# If the mount attempt takes longer than 30 seconds, it will give up.

[Install]
# Ensures this mount is activated at boot.
WantedBy=multi-user.target
# Mounts the share when the system reaches multi-user mode (normal operation).

Set mount unit file permissions

  • Make sure you have set the correct permissions and ownership for systemd mount files.
  • Correct Owner and Group: sudo chown root:root /etc/systemd/system/var-home-<username>-retrodeck.mount
  • Correct File Permissions: sudo chmod u=rw,g=r,o=r /etc/systemd/system/var-home-<username>-retrodeck.mount (u=rw → User (root) gets read & write; g=r → Group (root) gets read-only.; o=r → Others get read-only)

Fixing SELinux Denial (under Bazzite)

By default Systemd is being denied access to the mount unit file due to SELinux policies.

Check Current SELinux Mode

Run:

getenforce
  • If it returns Enforcing, SELinux is actively blocking access.
  • If it returns Permissive, it logs issues but doesn’t enforce them.

Relabel the Mount Unit File

Since the file is in /etc/systemd/system/, it should have the correct SELinux label. To fix it:

sudo restorecon -v /etc/systemd/system/var-home-<username>-retrodeck.mount

Now reload Systemd, enable Auto-Start, and start the SMB mount immediately

  • Reload Systemd to recognize New or modified units: sudo systemctl daemon-reload
    • Forces systemd to reload all unit files (services, mounts, timers, etc.).
    • Necessary when adding, modifying, or deleting .mount files, since systemd does not automatically detect changes.
    • Without this, systemd might not recognize new or modified units, leading to errors when enabling or starting them.
  • Enable the mount to Auto-Start at boot: sudo systemctl enable var-home-<username>-retrodeck.mount
    • Creates a symbolic link in /etc/systemd/system/multi-user.target.wants/ pointing to your mount file.
    • Ensures that systemd automatically mounts the SMB share every time the system boots.
    • This does not immediately mount it—it just sets it up for future boots.
  • Start (mount) the SMB share immediately: sudo systemctl start var-home-<username>-retrodeck.mount
    • Manually triggers the mounting of the SMB share right now, without waiting for a reboot.
    • If successful, the mount point (/var/home/<username>/retrodeck) should now show the contents of the SMB share.
    • If there are errors (e.g., wrong credentials, network issues), it will fail, but logs can be checked using journalctl -xe.
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