diff --git a/conf/mount_disk.sh b/conf/mount_disk.sh
index c72071d..dd14c41 100755
--- a/conf/mount_disk.sh
+++ b/conf/mount_disk.sh
@@ -8,7 +8,7 @@ then
     do
         i=$(( i + 1 ))
     done
-    echo $i
+    echo $i > $datadir/nbd_index
     modprobe nbd max_part=$(( i + 1 ))
     qemu-nbd --connect /dev/nbd$i $datadir/garage_data.qcow2
     if [[ "$format" = "true" ]]
diff --git a/conf/systemd.service b/conf/systemd.service
index c6a7b82..b3f3e89 100644
--- a/conf/systemd.service
+++ b/conf/systemd.service
@@ -8,7 +8,7 @@ User=__APP__
 Environment='RUST_LOG=garage=info' 'VIRTUALISATION=__VIRTUALISATION__'   'RUST_BACKTRACE=1'
 ExecStartPre=+__FINALPATH__/mount_disk.sh 
 ExecStart=__FINALPATH__/garage -c __FINALPATH__/garage.toml server
-ExecStopPost=+__FINALPATH__/umount_disk.sh __NBD_INDEX__
+ExecStopPost=+__FINALPATH__/umount_disk.sh 
 WorkingDirectory=__FINALPATH__/
 StandardOutput=append:/var/log/__APP__/__APP__.log
 StandardError=inherit
diff --git a/conf/umount_disk.sh b/conf/umount_disk.sh
index 7cc5880..c5a69ce 100755
--- a/conf/umount_disk.sh
+++ b/conf/umount_disk.sh
@@ -1,7 +1,8 @@
 #!/bin/bash
 if [ "$VIRTUALISATION" = "true" ] 
 then
-    nbd=$1
+     datadir=__DATADIR__
+    nbd=$(cat $datadir/nbd_index)
     umount  /dev/nbd$nbd
     qemu-nbd --disconnect  /dev/nbd$nbd
 fi
diff --git a/scripts/install b/scripts/install
index 88b9fbb..b8df9e6 100755
--- a/scripts/install
+++ b/scripts/install
@@ -130,8 +130,6 @@ ynh_app_setting_set --app=$app --key=port --value=$port
 port_api=$(ynh_find_port --port=5000)
 ynh_app_setting_set --app=$app --key=port_api --value=$port_api
 
-nbd_index=127
-
 
 # Optional: Expose this port publicly
 # (N.B.: you only need to do this if the app actually needs to expose the port publicly.
@@ -273,8 +271,7 @@ if [ "$virtualisation" = "true" ]
 then
 	# to be sure to not exceed size limit, i use a virtual disk with a fix size to have a max limit size.
 	qemu-img create -f qcow2 $datadir/garage_data.qcow2 "$weight"G
-	nbd_index=$($final_path/mount_disk.sh true)
-	ynh_app_setting_set --app=$app --key=nbd_index --value=$nbd_index
+	$final_path/mount_disk.sh true
 fi
 
 # FIXME: this should be managed by the core in the future
@@ -289,7 +286,7 @@ chown -R $app:$app "$datadir"
 
 if [ "$virtualisation" = "true" ]
 then
-	$final_path/umount_disk.sh $nbd_index
+	$final_path/umount_disk.sh
 fi
 
 #=================================================
diff --git a/scripts/remove b/scripts/remove
index 83d917e..4058727 100755
--- a/scripts/remove
+++ b/scripts/remove
@@ -28,7 +28,6 @@ final_path=$(ynh_app_setting_get --app=$app --key=final_path)
 virtualisation=$(ynh_app_setting_get --app=$app --key=virtualisation)
 if [ "$virtualisation" = "true" ]
 then
-	nbd_index=$(ynh_app_setting_get --app=$app --key=nbd_index)
 	export VIRTUALISTATION=true
 fi
 #=================================================
@@ -81,7 +80,7 @@ then
 	ynh_script_progression --message="umount virtual disk..."  --weight=1
 
 	# Remove the app directory securely
-	$final_path/umount_disk.sh  $nbd_index
+	$final_path/umount_disk.sh
 fi
 #=================================================
 # REMOVE APP MAIN DIR
diff --git a/scripts/restore b/scripts/restore
index e199ed4..eea7182 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -83,12 +83,11 @@ then
 	ynh_install_app_dependencies $pkg_dependencies_virtualisation
 	# to be sure to not exceed size limit, i use a virtual disk with a fix size to have a max limit size.
 	qemu-img create -f qcow2 $datadir/garage_data.qcow2 "$weight"G
-	nbd_index=$($final_path/mount_disk.sh "$datadir" true)
-	ynh_app_setting_set --app=$app --key=nbd_index --value=$nbd_index
+	$final_path/mount_disk.sh true
 fi
 
 
-# FIXME: this should be managed by the core in the future
+# # FIXME: this should be managed by the core in the future
 # Here, as a packager, you may have to tweak the ownerhsip/permissions
 # such that the appropriate users (e.g. maybe www-data) can access
 # files in some cases.