diff --git a/scripts/_common.sh b/scripts/_common.sh
index 06be71d..398a873 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -15,7 +15,6 @@ pkg_dependencies="php${YNH_PHP_VERSION}-cli php${YNH_PHP_VERSION}-mysql php${YNH
 #=================================================
 set_permissions () {
 
-    ynh_set_default_perm $final_path
     find $final_path -type f -name "*.php" -print0 | xargs -0 chmod 400 \
 	    || echo "No file to modify"
     #chown root: $final_path/application/config/config.php
@@ -28,81 +27,6 @@ set_permissions () {
 # COMMON HELPERS
 #=================================================
 
-ynh_set_default_perm () {
-    local DIRECTORY=$1
-    # Set permissions
-    chown -R $app:www-data $DIRECTORY
-    chmod -R 440 $DIRECTORY
-    find $DIRECTORY -type d -print0 | xargs -0 chmod 550 \
-	    || echo "No file to modify"
-
-}
-
-# Save listed var in YunoHost app settings 
-# usage: ynh_save_args VARNAME1 [VARNAME2 [...]]
-ynh_save_args () {
-    for var in $@;
-    do
-        local setting_var="$var"
-        if [ "$var" == "path_url" ]; then
-            setting_var="path"
-        fi
-        ynh_app_setting_set $app $setting_var ${!var}
-    done
-}
-
-# usage: ynh_save_persistent MODE RELATIVE_PATH 
-ynh_save_persistent () {
-    local TYPE=$1
-    local DIR=/tmp/ynh-persistent/$app
-    set +u
-    i=${#YNH_PERSISTENT_DIR[@]}
-    i=${i:-0}
-    set -u
-    [ "$i" -eq "0" ] && ynh_secure_remove $DIR && mkdir -p $DIR
-    if [ -e $final_path/$2  ]; then
-        mv $final_path/$2 $DIR/$i
-        YNH_PERSISTENT_MODE[$i]=$1
-        YNH_PERSISTENT_DIR[$i]=$2
-    fi
-}
-
-ynh_keep_if_no_upgrade () {
-    for elt in $@;
-    do
-        ynh_save_persistent KEEP_IF_NO_UPGRADE $elt
-    done
-}
-ynh_keep () {
-    for elt in $@;
-    do
-        ynh_save_persistent KEEP $elt
-    done
-}
-# usage: ynh_restore_persistent
-ynh_restore_persistent () {
-    local DIR=/tmp/ynh-persistent/$app
-    if [ -d $DIR ]; then
-        i=0
-        for PERSISTENT_DIR in "${YNH_PERSISTENT_DIR[@]}";
-        do
-            if [ "${YNH_PERSISTENT_MODE[$i]}" = "KEEP_IF_NO_UPGRADE" ]; then
-                if [ ! -e $final_path/$PERSISTENT_DIR ]; then
-                    mv $DIR/$i $final_path/$PERSISTENT_DIR
-                fi
-            else
-                if [ -e $final_path/$PERSISTENT_DIR ]; then
-                    ynh_secure_remove $final_path/$PERSISTENT_DIR
-                fi
-                mv $DIR/$i $final_path/$PERSISTENT_DIR
-            fi
-            ((i+=1))
-        done
-        ynh_secure_remove $DIR
-    fi
-
-}
-
 # Send an email to inform the administrator
 #
 # usage: ynh_send_readme_to_admin app_message [recipients]