Proxmox CIFS Share Mount Wizard Script

proxmox-lxc-cifs-share.sh

#!/bin/bash

# This script is designed to assist in mounting CIFS/SMB shares to a Proxmox LXC container.
# It automates the process of creating a mount point on the Proxmox VE (PVE) host, adding the
# CIFS share to the /etc/fstab for persistent mounts, and configuring the LXC container to
# recognize the share. This script is intended for use on a Proxmox Virtual Environment and
# requires an LXC container to be specified that will access the mounted share.
#
# Prerequisites:
# - Proxmox Virtual Environment setup.
# - An LXC container already created and running on Proxmox.
# - CIFS/SMB share details (hostname/IP, share name, SMB username, and password).
# - Root privileges on the Proxmox host.
#
# How to Use:
# 1. Ensure the target LXC container is running before executing this script.
# 2. Run this script as root or with sudo privileges.
# 3. Follow the prompts to enter the required information for the CIFS/SMB share
#    and the LXC container details.
#
# Note: This script must be run as root to modify system files and perform mount operations.

# Ensure the script is run as root
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi

# Ask user for necessary inputs
read -p "Enter the folder name (e.g., nas_rwx): " folder_name
read -p "Enter the CIFS hostname or IP (e.g., NAS): " cifs_host
read -p "Enter the share name (e.g., media): " share_name
read -p "Enter SMB username: " smb_username
read -sp "Enter SMB password: " smb_password && echo
read -p "Enter the LXC ID: " lxc_id
read -p "Enter the username within the LXC that needs access to the share (e.g., jellyfin, plex): " lxc_username

# Step 1: Configure LXC
echo "Creating group 'lxc_shares' with GID=10000 in LXC..."
pct exec $lxc_id -- groupadd -g 10000 lxc_shares

echo "Adding user $lxc_username to group 'lxc_shares'..."
pct exec $lxc_id -- usermod -aG lxc_shares $lxc_username

echo "Shutting down the LXC..."
pct stop $lxc_id

# Wait for the LXC to stop
while [ "$(pct status $lxc_id)" != "status: stopped" ]; do
  echo "Waiting for LXC $lxc_id to stop..."
  sleep 1
done

# Step 2: Configure PVE host
# Create mount point
echo "Creating mount point on PVE host..."
mkdir -p /mnt/lxc_shares/$folder_name

# Check if the fstab entry exists
fstab_entry="//${cifs_host}/${share_name} /mnt/lxc_shares/${folder_name} cifs _netdev,x-systemd.automount,noatime,nobrl,uid=100000,gid=110000,dir_mode=0770,file_mode=0770,username=${smb_username},password=${smb_password} 0 0"
if ! grep -q "//${cifs_host}/${share_name} /mnt/lxc_shares/${folder_name}" /etc/fstab ; then
    echo "Adding NAS CIFS share to /etc/fstab with nobrl option..."
    echo "$fstab_entry" >> /etc/fstab
else
    echo "Entry for ${cifs_host}/${share_name} on /mnt/lxc_shares/${folder_name} already exists in /etc/fstab."
fi

# Reload systemd to recognize changes to fstab
echo "Reloading systemd daemon to apply fstab changes..."
systemctl daemon-reload

# Before mounting, ensure the mount point is not already in use
if mountpoint -q "/mnt/lxc_shares/$folder_name"; then
    echo "Unmounting the already mounted share to avoid conflicts..."
    umount -l "/mnt/lxc_shares/$folder_name"
fi

# Mount the share
echo "Mounting the share on the PVE host..."
mount "/mnt/lxc_shares/$folder_name"

# Add a bind mount of the share to the LXC config
echo "Determining the next available mount point index..."
config_file="/etc/pve/lxc/${lxc_id}.conf"
if [ -f "$config_file" ]; then
    last_mp_index=$(grep -oP 'mp\d+:' "$config_file" | grep -oP '\d+' | sort -nr | head -n1)
    next_mp_index=$((last_mp_index + 1))
else
    next_mp_index=0
fi

echo "Adding a bind mount of the share to the LXC config..."
lxc_config_entry="mp${next_mp_index}: /mnt/lxc_shares/${folder_name},mp=/mnt/${folder_name}"
echo "$lxc_config_entry" >> "$config_file"

# Step 3: Start the LXC
echo "Starting the LXC..."
pct start $lxc_id

echo "Configuration complete."

This is great - thank you.
I do think you need to revert to the original instructions in the first part of step 1 from the revision on March 7.

10000 in the LXC will map correctly to 110000 in the PVE
(mapping 110000 in the LXC will incorrectly map on the PVE)

When I made this change it’s working great on my tteck Jellyfin container.

echo "Creating group 'lxc_shares' with GID=10000 in LXC..."
pct exec $lxc_id -- groupadd -g 10000 lxc_shares```

@rucknapucknavitz

No problem, I have revised the script with the change you requested. Thank you.

I will be changing the following line as well to use 10000 instead of 110000:
https://github.com/NorkzYT/Wolflith/blob/b10bc7b4680bf240a1055ea7d7f36435107e6c15/Ansible/playbooks/provision-proxmox-lxc.yml#L145

Hi there for some reason not working with me, new to proxmox that is why Im using this, thanks btw, but even though it says complete it doesnt show. I tried it with the *arr that are in a lxc. Also type on line 34 read -sp "Enter SMB password: " smb_password && echo

the message im getting is mount error(16): Device or resource busy. Im trying to connect it to my synology rackstation so not sure what could be giving that error.

This works great, but I'm having an issue with sub folder permissions. Any existing folder in the share I cannot write to so I see errors in the web GUIs for the LXCs. If I create a folder in the root from the LXC, then it's writeable, so it's existing folders that are the issue.

The permissions look the same, test3 is a folder I created within the LXC, Movies is one I created inside the NAS server before connecting the LXC.

I can connect to test3 fine, but I cannot write to Movies or any of the other subfolders (root folder is fine).

This isn’t a script issue so not really a topic for this thread, it’s a permissions issue.
Checkout some chmod tutorials online, like this one: https://www.tomshardware.com/how-to/change-file-directory-permissions-linux

This isn’t a script issue so not really a topic for this thread, it’s a permissions issue. Checkout some chmod tutorials online, like this one: https://www.tomshardware.com/how-to/change-file-directory-permissions-linux

this script is supposed to fix the permissions issue with the LXCs. Hence why I asked.

Sounds like it could be a share host permission issue, unless you’re sharing directly from the proxmox host?

I'm sharing from a Cockpit LXC on the same host.

Problem is now, since rebooting, the host won't even mount that share now.

There's a bug, if you have snapshots saved of the LXC. The Mp0: isn't getting added to the "running" version, but instead to the saved snapshot.

Thanks for the script. Working great! On my version of proxmox I had to make one tiny modification and change from:
read -sp "Enter SMB password: " smb_password && echo to read -p "Enter SMB password: " smb_password && echo

Great and useful script. Unfortunately I'm getting the error: Stale file handle when trying to open a txt file on my share.
Any ideas?

Edit:
Found the fix for my problem.

pvesm set --options noserverino

Thank you so much! All my attempts to achieve this on my own have been a waste of time with no success...