diff --git a/scripts/_common.sh b/scripts/_common.sh
index 7bfeebd..4ed79bf 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -5,220 +5,6 @@
 #=================================================
 nodejs_version=8.11.4
 
-#=================================================
-# BACKUP
-#=================================================
-
-HUMAN_SIZE () {	# Transforme une taille en Ko en une taille lisible pour un humain
-	human=$(numfmt --to=iec --from-unit=1K $1)
-	echo $human
-}
-
-CHECK_SIZE () {	# Vérifie avant chaque backup que l'espace est suffisant
-	file_to_analyse=$1
-	backup_size=$(du --summarize "$file_to_analyse" | cut -f1)
-	free_space=$(df --output=avail "/home/yunohost.backup" | sed 1d)
-
-	if [ $free_space -le $backup_size ]
-	then
-		ynh_print_err "Espace insuffisant pour sauvegarder $file_to_analyse."
-		ynh_print_err "Espace disponible: $(HUMAN_SIZE $free_space)"
-		ynh_die "Espace nécessaire: $(HUMAN_SIZE $backup_size)"
-	fi
-}
-
-#=================================================
-# EXPERIMENTAL HELPERS
-#=================================================
-
-n_install_dir="/opt/node_n"
-node_version_path="$n_install_dir/n/versions/node"
-# N_PREFIX is the directory of n, it needs to be loaded as a environment variable.
-export N_PREFIX="$n_install_dir"
-
-# Install Node version management
-#
-# [internal]
-#
-# usage: ynh_install_n
-ynh_install_n () {
-	echo "Installation of N - Node.js version management" >&2
-	# Build an app.src for n
-	mkdir -p "../conf"
-	echo "SOURCE_URL=https://github.com/tj/n/archive/v2.1.7.tar.gz
-SOURCE_SUM=2ba3c9d4dd3c7e38885b37e02337906a1ee91febe6d5c9159d89a9050f2eea8f" > "../conf/n.src"
-	# Download and extract n
-	ynh_setup_source "$n_install_dir/git" n
-	# Install n
-	(cd "$n_install_dir/git"
-	PREFIX=$N_PREFIX make install 2>&1)
-}
-
-# Load the version of node for an app, and set variables.
-#
-# ynh_use_nodejs has to be used in any app scripts before using node for the first time.
-#
-# 2 variables are available:
-#   - $nodejs_path: The absolute path of node for the chosen version.
-#   - $nodejs_version: Just the version number of node for this app. Stored as 'nodejs_version' in settings.yml.
-# And 2 alias stored in variables:
-#   - $nodejs_use_version: An old variable, not used anymore. Keep here to not break old apps
-#     NB: $PATH will contain the path to node, it has to be propagated to any other shell which needs to use it.
-#     That's means it has to be added to any systemd script.
-#
-# usage: ynh_use_nodejs
-ynh_use_nodejs () {
-	nodejs_version=$(ynh_app_setting_get $app nodejs_version)
-
-	nodejs_use_version="echo \"Deprecated command, should be removed\""
-
-	# Get the absolute path of this version of node
-	nodejs_path="$node_version_path/$nodejs_version/bin"
-
-	# Load the path of this version of node in $PATH
-	[[ :$PATH: == *":$nodejs_path"* ]] || PATH="$nodejs_path:$PATH"
-}
-
-# Install a specific version of nodejs
-#
-# n (Node version management) uses the PATH variable to store the path of the version of node it is going to use.
-# That's how it changes the version
-#
-# ynh_install_nodejs will install the version of node provided as argument by using n.
-#
-# usage: ynh_install_nodejs [nodejs_version]
-# | arg: nodejs_version - Version of node to install.
-#        If possible, prefer to use major version number (e.g. 8 instead of 8.10.0).
-#        The crontab will handle the update of minor versions when needed.
-ynh_install_nodejs () {
-	# Use n, https://github.com/tj/n to manage the nodejs versions
-	nodejs_version="$1"
-
-	# Create $n_install_dir
-	mkdir -p "$n_install_dir"
-
-	# Load n path in PATH
-	CLEAR_PATH="$n_install_dir/bin:$PATH"
-	# Remove /usr/local/bin in PATH in case of node prior installation
-	PATH=$(echo $CLEAR_PATH | sed 's@/usr/local/bin:@@')
-
-	# Move an existing node binary, to avoid to block n.
-	test -x /usr/bin/node && mv /usr/bin/node /usr/bin/node_n
-	test -x /usr/bin/npm && mv /usr/bin/npm /usr/bin/npm_n
-
-	# If n is not previously setup, install it
-	if ! test $(n --version > /dev/null 2>&1)
-	then
-		ynh_install_n
-	fi
-
-	# Modify the default N_PREFIX in n script
-	ynh_replace_string "^N_PREFIX=\${N_PREFIX-.*}$" "N_PREFIX=\${N_PREFIX-$N_PREFIX}" "$n_install_dir/bin/n"
-
-	# Restore /usr/local/bin in PATH
-	PATH=$CLEAR_PATH
-
-	# And replace the old node binary.
-	test -x /usr/bin/node_n && mv /usr/bin/node_n /usr/bin/node
-	test -x /usr/bin/npm_n && mv /usr/bin/npm_n /usr/bin/npm
-
-	# Install the requested version of nodejs
-	n $nodejs_version
-
-	# Find the last "real" version for this major version of node.
-	real_nodejs_version=$(find $node_version_path/$nodejs_version* -maxdepth 0 | sort --version-sort | tail --lines=1)
-	real_nodejs_version=$(basename $real_nodejs_version)
-
-	# Create a symbolic link for this major version if the file doesn't already exist
-	if [ ! -e "$node_version_path/$nodejs_version" ]
-	then
-		ln --symbolic --force --no-target-directory $node_version_path/$real_nodejs_version $node_version_path/$nodejs_version
-	fi
-
-	# Store the ID of this app and the version of node requested for it
-	echo "$YNH_APP_ID:$nodejs_version" | tee --append "$n_install_dir/ynh_app_version"
-
-	# Store nodejs_version into the config of this app
-	ynh_app_setting_set $app nodejs_version $nodejs_version
-
-	# Build the update script and set the cronjob
-	ynh_cron_upgrade_node
-
-	ynh_use_nodejs
-}
-
-# Remove the version of node used by the app.
-#
-# This helper will check if another app uses the same version of node,
-# if not, this version of node will be removed.
-# If no other app uses node, n will be also removed.
-#
-# usage: ynh_remove_nodejs
-ynh_remove_nodejs () {
-	nodejs_version=$(ynh_app_setting_get $app nodejs_version)
-
-	# Remove the line for this app
-	sed --in-place "/$YNH_APP_ID:$nodejs_version/d" "$n_install_dir/ynh_app_version"
-
-	# If no other app uses this version of nodejs, remove it.
-	if ! grep --quiet "$nodejs_version" "$n_install_dir/ynh_app_version"
-	then
-		$n_install_dir/bin/n rm $nodejs_version
-	fi
-
-	# If no other app uses n, remove n
-	if [ ! -s "$n_install_dir/ynh_app_version" ]
-	then
-		ynh_secure_remove "$n_install_dir"
-		ynh_secure_remove "/usr/local/n"
-	fi
-}
-
-# Set a cron design to update your node versions
-#
-# [internal]
-#
-# This cron will check and update all minor node versions used by your apps.
-#
-# usage: ynh_cron_upgrade_node
-ynh_cron_upgrade_node () {
-	# Build the update script
-	cat > "$n_install_dir/node_update.sh" << EOF
-#!/bin/bash
-version_path="$node_version_path"
-n_install_dir="$n_install_dir"
-# Log the date
-date
-# List all real installed version of node
-all_real_version="\$(find \$version_path/* -maxdepth 0 -type d | sed "s@\$version_path/@@g")"
-# Keep only the major version number of each line
-all_real_version=\$(echo "\$all_real_version" | sed 's/\..*\$//')
-# Remove double entries
-all_real_version=\$(echo "\$all_real_version" | sort --unique)
-# Read each major version
-while read version
-do
-	echo "Update of the version \$version"
-	sudo \$n_install_dir/bin/n \$version
-	# Find the last "real" version for this major version of node.
-	real_nodejs_version=\$(find \$version_path/\$version* -maxdepth 0 | sort --version-sort | tail --lines=1)
-	real_nodejs_version=\$(basename \$real_nodejs_version)
-	# Update the symbolic link for this version
-	sudo ln --symbolic --force --no-target-directory \$version_path/\$real_nodejs_version \$version_path/\$version
-done <<< "\$(echo "\$all_real_version")"
-EOF
-
-	chmod +x "$n_install_dir/node_update.sh"
-
-	# Build the cronjob
-	cat > "/etc/cron.daily/node_update" << EOF
-#!/bin/bash
-$n_install_dir/node_update.sh >> $n_install_dir/node_update.log
-EOF
-
-	chmod +x "/etc/cron.daily/node_update"
-}
-
 #=================================================
 
 # Start or restart a service and follow its booting