Store games on a NAS

Instead of using the internal storage or an external USB key/hard drive to store your userdata (games, saves, configuration, etc.), you can use a NAS (Network Attached Storage) instead. Of course you can also use your NAS as a backup target for all of your userdata and games for desaster recovery of your Batocera system as described below, just in case of…well…you name it.

You will need to replace the sharedevice=INTERNAL line with sharedevice=NETWORK inside batocera-boot.conf. This file is on the boot partition of the Batocera system. If on a removable drive, you can edit it from any computer as it is in a readable FAT32 file system (don't use Windows Notepad).

Batocera uses a simpler syntax than standard Linux network mounting. For each network share you'd like to attach, add an additional line below sharedevice beginning with sharenetwork_smb#= (for most Windows Samba shares) or sharenetwork_nfs# (for most Linux Network File System shares) where # is the number of the share from 0-9 (yes, this does mean you're limited to only ten shares per type of share, this limit may be changed in the future). Following this, put in the keyword for the appropriate directory you want to replace in Batocera (as listed below).

There are the pre-defined keywords you can use:

• For the whole user data directory, SHARE
• For the roms directory, ROMS
• For the bios directory, BIOS
• For the saves directory, SAVES
• For custom menu background music, MUSIC
• For custom bezels, DECORATIONS
• For screenshots taken in game or with batocera-screenshot, SCREENSHOTS
• For themes, THEMES
• For cheats databases, CHEATS
• For sounds, SOUNDS (v32 and above)
• For magazine and videos, LIBRARY
• For the boot splash, SPLASH

You can add any combination of the above (except SHARE as that includes everything) by adding additional lines.

@[IP-address]:[share-name]/[path/to/directory]:[option1-name]=[option1-value],[option2-name]=[option2-value],[etc.]

Then add the @ symbol, the IP address/hostname of the device with the share, the : character, the name of the share followed by a /, then the path to the directory (using Unix syntax / instead of \), another : character and then any additional options required for the share separated by a comma (,) (guest shares need only :guest as an option, password protected shares need :username=[your-username],password=[your-password]). Syntax:

sharenetwork_[smb-or-nfs][0-9]=[keyword]@[IP-address]:[share-name]/[path/to/directory]:[option1-name]=[option1-value],[option2-name]=[option2-value],[etc.]

Examples below.

Windows shares can use identification or a guest account to connect.

In the following examples, the Windows CIFS share called Documents has a folder named batocera which contains the folder structure of Batocera's userdata directory. The IP address of the Windows shared server is 192.168.0.1 in this example. If applicable, you can use the hostname of your NAS instead, however this may have issues with particular routers.

  sharedevice=NETWORK
  sharenetwork_smb1=SHARE@192.168.0.1:Documents/batocera:guest

  sharedevice=NETWORK
  sharenetwork_smb1=ROMS@192.168.0.1:Documents/batocera/roms:guest

  sharedevice=NETWORK
  sharenetwork_smb1=ROMS@192.168.0.1:Documents/batocera/roms:username=john,password=wayne

  sharedevice=NETWORK
  sharenetwork_smb1=ROMS@192.168.0.1:Documents/batocera/roms:guest
  sharenetwork_smb2=SAVES@192.168.0.1:Documents/batocera/saves:guest
  sharenetwork_smb3=BIOS@192.168.0.1:Documents/batocera/bios:guest

In several cases, you need to add SMB options, for instance if you NAS requires a specific CIFS version:

sharenetwork_smb1=ROMS@192.168.0.1:Documents/Batocera/roms:guest,vers=1.0

CIFS version is needed for several NAS vendors:

• when using and Orange Livebox as a NAS, or on Synology (tested on a DS418play), you need vers=1.0
• if you use OpenMediaVault 5, you need vers=3.0

In this kind of setup, make sure that:

• you provide the exact name your SMB share on the NAS (Documents/Batocera/roms in the example above is the path from your NAS export)
• you have the right user authentication (username=john,password=wayne in the example above) and, if you use anonymous guest access, that you have write access enabled, so that Batocera can write the updated in the gamelist.xml files, and download scraped metadata like thumbnails or video snapshots.

  sharedevice=NETWORK
  sharenetwork_nfs1=SHARE@192.168.0.1:/mnt/Documents/batocera

  sharedevice=NETWORK
  sharenetwork_nfs1=ROMS@192.168.0.1:/mnt/Documents/batocera/roms:vers=4

  sharedevice=NETWORK
  sharenetwork_nfs1=ROMS@192.168.0.1:/mnt/Documents/batocera/roms
  sharenetwork_nfs2=SAVES@192.168.0.1:/mnt/Documents/batocera/saves
  sharenetwork_nfs3=BIOS@192.168.0.1:/mnt/Documents/batocera/bios

Make sure you escape special characters in your CIFS passwords if you have some. To escape a character, put a \ in front of it. To escape a \ itself, use \\.

For troubleshooting purposes, you have /tmp/mountNetwork.log and /tmp/mountNetwork.err that will give you some insights on the mount failures if needed.

It is possible to map individual folders with sharenetwork_cmd# if you are familiar with standard Linux network storage mounting. Examples of mapping other directories via sharenetwork_cmd:

sharenetwork_cmd1=mount.cifs -o guest //192.168.0.1/Documents/batocera/music /userdata/music
sharenetwork_cmd2=mount.cifs -o guest //192.168.0.1/Documents/batocera/cheats /userdata/cheats
sharenetwork_cmd3=mount.cifs -o guest //192.168.0.1/Documents/batocera/screenshots /userdata/screenshots
sharenetwork_cmd4=mount.cifs -o guest //192.168.0.1/Documents/batocera/themes /userdata/themes

This will only work if sharedevice=NETWORK. You can also use this to just mount anything with acceptable bash commands, including folders from local drives, etc.

Batocera has a unique root user, so all files accessed on the share are from the root user, which can conflict with how your other NFS clients access files. You should check how the file permissions are declared on your NFS server, but a common way to make sure your file permissions are managed correctly is to map the file rights to the UID of the user that will access these files locally. Typically, if your NFS shares are defined in /etc/exports and you want to give access to a user with UID/GID of 1000, you can make it with:

/media/games/batocera 192.168.0.1(rw,sync,all_squash,anonuid=1000,anongid=1000,no_subtree_check)

In this example we will cover how to automatically backup the most important two data folders /userdata (which contains all important (custom) configurations) and /roms (which contains all of your games) of your Batocera system so that in case of emergency you will have all your data in a recoverable state.

For this tutorial you will need to enable the following services on your Synology NAS via the Synology DSM web GUI as follows:

• SMB → Navigate to Control Panel → File Services → SMB → Check Enable SMB service:
  
• rsync → Navigate to Control Panel → File Services → rsync → Check Enable rsync service and for SSH encryption port: set the value 22:
  
• SSH → Navigate to Control Panel → Terminal & SNMP → Check Enable SSH service and for Port: set the value 22:
  

Next, you will need to create a user (standard local user without administrative privileges) for backup purposes on your Synology NAS. For this tutorial we will name the user backup.

Next, you will need to create a shared folder where your Batocera data can be stored to. For this tutorial we will name the shared folder batoceraBackup. You have to set read/write permissions on that shared folder for the specific user you have created before:

Next, you will need to create a firewall rule on your Synology NAS so that your Batocera system can send its data over the network to the Synology NAS. The rule must allow the following two services:

• Windows file server
• Encrypted terminal service (includes encrypted rsync and SFTP)

In addition it is also strongly(!) recommended to limit the firewall rule to allow only the static IP address of your Batocera system:

Now SSH into your Batocera system and execute the following command to create a custom scripts folder:

mkdir -p /userdata/scripts

Now create the following script file:

nano /userdata/scripts/romsBackup.sh

And paste the following content (replace <your_password> with the according backup user its user password and <Synology_NAS_IP_address> with the static IP address of your Synology NAS):

#!/bin/sh
USER=backup
PASS=<your_password>
SHARE=//<Synology_NAS_IP_address>/batoceraBackup
MOUNT_POINT=/tmp/tempMountFolder
mkdir -p "$MOUNT_POINT"
mount -t cifs -o username="$USER",password="$PASS" "$SHARE" "$MOUNT_POINT"
rsync -Pav --delete -e ssh /userdata/roms "$MOUNT_POINT"
cd /tmp
umount -f "$MOUNT_POINT"
exit 0

Save the file and quit the editor.

Now create the following script file:

nano /userdata/scripts/userdataBackup.sh

And paste the following content (replace <your_password> with the according backup user its user password and <Synology_NAS_IP_address> with the static IP address of your Synology NAS):

#!/bin/sh
USER=backup
PASS=<your_password>
SHARE=//<Synology_NAS_IP_address>/batoceraBackup
MOUNT_POINT=/tmp/tempMountFolder
mkdir -p "$MOUNT_POINT"
mount -t cifs -o username="$USER",password="$PASS" "$SHARE" "$MOUNT_POINT"
cd "$MOUNT_POINT"
tar cfv "$MOUNT_POINT"/batoceraBackup.tar /userdata --exclude=roms --exclude=saves/flatpak
rm -rf ./batoceraBackup.tar
cd /tmp
umount -f "$MOUNT_POINT"
exit 0

Save the file and quit the editor.

Now create the following script file:

nano /userdata/scripts/systemBackup.sh

And paste the following content:

#!/bin/sh
/userdata/scripts/romsBackup.sh
/userdata/scripts/userdataBackup.sh
shutdown -h now

Save the file and quit the editor.

Now make all three scripts executable by executing:

chmod +x /userdata/scripts/*.sh

Now let's do the automation part:

SSH with user root into your Synology NAS (Unfortunately you have to use a Synology user which is part of the administrators group, otherwise SSH access will be declined. To avoid any permission issues, we will user root here.). Then execute the following commands (replace <Batocera_IP_address> with the static IP address of your Batocera system):

ssh-keygen

cat ~/.ssh/id_rsa.pub | ssh root@<Batocera_IP_address> 'cat >> /userdata/system/ssh/authorized_keys'

Insert the Batocera root user's password (Default password: linux).

Now go back to the Synology DSM web GUI and create the according automation task: Navigate to Control Panel → Task Scheduler → Create → Scheduled Task → User-defined script → General: For Task insert a custom task name (e.g. batoceraBackup) and for user choose root → Schedule: Configure a desired custom schedule → Task Settings: For User-defined script insert the following (replace <Batocera_MAC_address> with the according MAC address of your Batocera system and <Synology_network_interface> with the according network interface name through which you want to send the magic packet to (the one which is within the same Layer 2 subnet as your Batocera system, e.g. eth0):

#!/bin/sh
sudo synonet --wake <Batocera_MAC_address> <Synology_network_interface>
sleep 30
ssh root@<Batocera_IP_address> sh ../scripts/systemBackup.sh

Confirm by clicking on OK.

That's it! Your scheduled backup automation should work now.