Persistent SMB Shares on Linux — From Manual Mount to Automount on Access

The Situation

You have one or more SMB shares on your local network that you need to access regularly from a Linux workstation. You want them to:

1. Show up in your file manager sidebar.
2. Survive a reboot.
3. Not block the boot process when the server is unreachable (e.g., VPN is off).
4. Connect automatically when you navigate to the folder.

On Windows or macOS, you right-click “Map Network Drive” and you’re done. On Linux, there are several layers to get right: packages, credentials, fstab, systemd, and file manager bookmarks. This post walks through each one.

Step 0: Install the Required Packages

You need two things: a client to browse shares and a mount helper for CIFS.

sudo apt install -y smbclient cifs-utils

• smbclient — command-line tool to list and access SMB shares (like an FTP client for SMB).
• cifs-utils — provides mount.cifs, required for mounting shares via mount or fstab.

Without cifs-utils, mount attempts will fail with a cryptic “cannot mount read-only” error — the kernel has CIFS support but no userspace helper to parse mount options.

Step 1: Discover Available Shares

Before mounting, find out what’s available on the server:

# Anonymous access
smbclient -L //SERVER -N

# With credentials
smbclient -L //SERVER -U YOUR_USER

# With a domain
smbclient -L //SERVER -U DOMAIN/YOUR_USER

You’ll see output like:

Sharename       Type      Comment
---------       ----      -------
documents       Disk      Shared documents
projects        Disk      Project files
IPC$            IPC       Remote IPC

Shares ending in $ (like ADMIN$, C$, IPC$) are hidden administrative shares — you typically don’t need these.

Verify access to a specific share before trying to mount it:

smbclient //SERVER/SHARE_NAME -U DOMAIN/YOUR_USER -c 'ls'

If this fails with NT_STATUS_ACCESS_DENIED, the share requires different credentials or permissions — fix that before proceeding.

Step 2: Quick Access via File Manager

The fastest way to access an SMB share is through your file manager’s address bar.

GNOME Files (Nautilus):

1. Press Ctrl+L to open the location bar.
2. Type smb://SERVER/SHARE_NAME and press Enter.
3. Enter your domain, username, and password when prompted.

KDE Dolphin / XFCE Thunar / Cinnamon Nemo: Same approach — type the smb:// URL in the address bar.

This uses GVFS under the hood and requires gvfs-backends (installed by default on most desktop Ubuntu/Fedora). It works but doesn’t survive a reboot and won’t show up as a regular path under /mnt.

Step 3: Store Credentials Securely

For persistent mounts, store your credentials in a file that only root can read:

sudo bash -c 'cat > /etc/smbcredentials' <<EOF
username=YOUR_USER
password=YOUR_PASS
domain=YOUR_DOMAIN
EOF
sudo chmod 600 /etc/smbcredentials

The chmod 600 ensures only root can read this file. Never put credentials directly in /etc/fstab — anyone who can read fstab (every user on the system) would see them.

If your share allows anonymous access, you won’t need a credentials file — use guest,sec=none as mount options instead.

Step 4: Create the Mount Point

sudo mkdir -p /mnt/my_share

Pick a path that makes sense. Common conventions:

• /mnt/share_name — traditional location
• /media/share_name — more common for removable media
• /srv/share_name — if it’s a data source for services

Step 5: Add the fstab Entry

Basic (mount at boot)

echo '//SERVER/SHARE_NAME /mnt/my_share cifs credentials=/etc/smbcredentials,uid=1000,gid=1000,iocharset=utf8,nofail 0 0' | sudo tee -a /etc/fstab

Key options:

With Automount (recommended)

The basic approach tries to mount at boot — if the server is unreachable (VPN off, server down), the mount silently fails. You’d then need to run sudo mount -a manually after connecting.

A better approach uses systemd automount — the share mounts only when you access the directory:

echo '//SERVER/SHARE_NAME /mnt/my_share cifs credentials=/etc/smbcredentials,uid=1000,gid=1000,iocharset=utf8,noauto,x-systemd.automount,x-systemd.idle-timeout=60,nofail 0 0' | sudo tee -a /etc/fstab

The additional options:

This is the best approach when you’re not always on the same network. The directory appears to exist, and the actual SMB connection only happens when something reads from it.

After editing fstab, reload systemd:

sudo systemctl daemon-reload
sudo mount -a

Verify:

ls /mnt/my_share

Step 6: Add a File Manager Bookmark

The mount at /mnt/my_share works from the terminal, but won’t appear in your file manager sidebar by default. Fix that:

echo "file:///mnt/my_share" >> ~/.config/gtk-3.0/bookmarks

Note the three slashes in file:/// — file:// is the protocol, and the third / is the root of the filesystem path. Two slashes will result in a broken bookmark.

Close and reopen your file manager. The share now appears in the sidebar.

Putting It All Together: A Setup Script

Here’s a reusable script that handles everything — install, credentials, fstab (with automount), and bookmarks. It’s idempotent: safe to run multiple times.

#!/bin/bash
set -e

BOOKMARK_FILE="$HOME/.config/gtk-3.0/bookmarks"
mkdir -p "$(dirname "$BOOKMARK_FILE")"

# Install cifs-utils if missing
if ! dpkg -s cifs-utils &>/dev/null; then
    echo "Installing cifs-utils..."
    sudo apt install -y cifs-utils
fi

mount_share() {
    local SHARE="$1"
    local MOUNT_POINT="$2"
    local MOUNT_OPTS="$3"
    local NAME="$4"

    echo ""
    echo "=== Setting up $NAME ==="

    sudo mkdir -p "$MOUNT_POINT"

    # Remove old fstab entry if present, then add correct one
    local FSTAB_LINE="$SHARE $MOUNT_POINT cifs $MOUNT_OPTS,uid=$(id -u),gid=$(id -g),iocharset=utf8,noauto,x-systemd.automount,x-systemd.idle-timeout=60,nofail 0 0"
    if grep -qF "$SHARE" /etc/fstab; then
        sudo sed -i "\|$SHARE|d" /etc/fstab
        echo "Removed old fstab entry"
    fi
    echo "$FSTAB_LINE" | sudo tee -a /etc/fstab >/dev/null
    echo "Added fstab entry with automount"

    # Reload and mount
    sudo systemctl daemon-reload
    sudo mount -a

    # Verify
    if mountpoint -q "$MOUNT_POINT"; then
        echo "Success! $NAME mounted at $MOUNT_POINT"
    else
        echo "ERROR: $NAME mount failed. Check dmesg for details."
    fi

    # Add Nautilus sidebar bookmark
    local BOOKMARK="file://$MOUNT_POINT"
    if ! grep -qF "$BOOKMARK" "$BOOKMARK_FILE" 2>/dev/null; then
        echo "$BOOKMARK" >> "$BOOKMARK_FILE"
        echo "Added $NAME bookmark to file manager sidebar"
    else
        echo "Bookmark already exists"
    fi
}

# --- Create credentials file if needed ---
CRED_FILE="/etc/smbcredentials"
if [ ! -f "$CRED_FILE" ]; then
    read -p "SMB Username: " SMB_USER
    read -sp "SMB Password: " SMB_PASS
    echo
    read -p "Domain: " SMB_DOMAIN

    sudo bash -c "cat > $CRED_FILE" <<EOF
username=$SMB_USER
password=$SMB_PASS
domain=$SMB_DOMAIN
EOF
    sudo chmod 600 "$CRED_FILE"
    echo "Credentials saved to $CRED_FILE"
fi

# --- Mount shares ---
mount_share "//SERVER/SHARE1" "/mnt/share1" "credentials=$CRED_FILE" "Share 1"
mount_share "//SERVER/SHARE2" "/mnt/share2" "credentials=$CRED_FILE" "Share 2"

echo ""
echo "=== All done! ==="

Customize the mount_share calls at the bottom for your shares. The script handles both fresh installs and updates to existing mounts.

Troubleshooting

“cannot mount read-only”

Install cifs-utils — this error means the mount helper is missing.

NT_STATUS_ACCESS_DENIED

Wrong credentials, wrong domain, or the share requires specific permissions. Test with smbclient first.

NT_STATUS_LOGON_FAILURE

Authentication failed. Check:

• Is the domain correct? Try with and without it.
• Is the password for this specific server (not your Linux login)?
• Some shares allow anonymous access — try -N flag with smbclient.

Mount works but file manager bookmark shows error

Check that the bookmark path has three slashes: file:///mnt/... not file://mnt/....

Shares don’t mount after reboot (without automount)

If VPN wasn’t connected at boot, nofail let the system start without mounting. Run sudo mount -a after connecting, or switch to the automount approach.

Permission denied on mounted files

Adjust uid and gid in the fstab options to match your user. Check with id -u and id -g.

Summary

The automount approach gives you the best of all worlds: the shares appear as regular directories, connect only when needed, disconnect when idle, and never block your boot process.