diff --git a/.VERSION b/.VERSION
index 1eb805bc..c60d416f 100644
--- a/.VERSION
+++ b/.VERSION
@@ -1 +1 @@
-v6.1.0
\ No newline at end of file
+v6.2.0-beta.1
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a621160d..a685acf6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 ## Changelog
+### v6.2.0-beta.1 (2022-06-13)
+* rewrite maintenance script ([#243 by @agross](https://github.com/buanet/ioBroker.docker/pull/243))
+* optimize container shutdown on SIGTERM ([as requested with #264 by @buzz0r](https://github.com/buanet/ioBroker.docker/pull/264))
 
 ### v6.1.0 (2022-03-01)
 * v6.1.0-beta.2 (2022-02-11)
@@ -8,8 +11,8 @@
   * optimize startup script logging
   * add breaks and optimize maintenance script (fixes [#233](https://github.com/buanet/ioBroker.docker/issues/233))
 * v6.1.0-beta.1 (2021-12-23)
-  * some more corrections in maintenance script ([#232 @agross](https://github.com/buanet/ioBroker.docker/pull/232)) 
-  * add auto confirm parameter to upgrade function in maintenance script ([#229 @thost96](https://github.com/buanet/ioBroker.docker/pull/229))
+  * some more corrections in maintenance script ([#232 by @agross](https://github.com/buanet/ioBroker.docker/pull/232)) 
+  * add auto confirm parameter to upgrade function in maintenance script ([#229 by @thost96](https://github.com/buanet/ioBroker.docker/pull/229))
   * add alias "m" for maintenance script
 
 ### v6.0.0 (2021-12-09)
@@ -96,7 +99,7 @@
 ### v4.1.0 (2020-01-17)
 * improved readme.md
 * v4.0.3-beta (2020-01-06)
-  * added support to restore backup on startup ([#56 @duffbeer2000](https://github.com/buanet/ioBroker.docker/pull/56))
+  * added support to restore backup on startup ([#56 by @duffbeer2000](https://github.com/buanet/ioBroker.docker/pull/56))
   * small fixes according to "docker best practices"
 * v4.0.2-beta (2019-12-10)
   * ~~added env for activating redis~~
@@ -116,13 +119,13 @@
 * v3.1.2-beta (2019-09-03)
   * using node 10 instead of node 8
 * v3.1.1-beta (2019-09-02)
-  * adding env for setting uid/ gid for iobroker-user ([#33 @mplogas](https://github.com/buanet/ioBroker.docker/pull/33))
+  * adding env for setting uid/ gid for iobroker-user ([#33 by @mplogas](https://github.com/buanet/ioBroker.docker/pull/33))
 
 ### v3.1.0 (2019-08-21)
 * v3.0.3-beta (2019-08-21)
   * switching base image from "debian:latest" to "debian:stretch"
 * v3.0.2-beta (2019-06-13)
-  * using gosu instead of sudo ([#26 @SchumyHao](https://github.com/buanet/ioBroker.docker/pull/26))
+  * using gosu instead of sudo ([#26 by @SchumyHao](https://github.com/buanet/ioBroker.docker/pull/26))
   * changing output of ioBroker logging
 * v3.0.1-beta (2019-05-18)
   * ~~switching back to iobroker-daemon for startup~~
diff --git a/debian/scripts/iobroker_startup.sh b/debian/scripts/iobroker_startup.sh
index f8e7122b..64aa9312 100644
--- a/debian/scripts/iobroker_startup.sh
+++ b/debian/scripts/iobroker_startup.sh
@@ -19,6 +19,8 @@ statesdbtype=$IOB_STATESDB_TYPE
 usbdevices=$USBDEVICES
 zwave=$ZWAVE
 
+pkill_timeout=10      # timeout for iobroker shutdown in seconds
+
 # Getting date and time for logging
 dati=`date '+%Y-%m-%d %H:%M:%S'`
 
@@ -497,8 +499,35 @@ echo "running" > /opt/scripts/.docker_config/.healthcheck
 shut_down() {
   echo ' '
   echo "Recived termination signal (SIGTERM)."
-  echo "Shutting down ioBroker..."
-  pkill -SIGTERM -u iobroker -f iobroker.js-controller
+  echo -n "Shutting down ioBroker"
+
+  local status timeout
+
+  timeout="$(date --date="now + $pkill_timeout sec" +%s)"
+  pkill -u iobroker -f iobroker.js-controller
+  status=$?
+  if (( status >= 2 )); then      # syntax error or fatal error
+    return 1
+  fi
+
+  if (( status == 1 )); then      # no processes matched
+    return
+  fi
+
+  # pgrep exits with status 1 when there are no matches
+  while pgrep -u iobroker > /dev/null; (( $? != 1 )); do
+    if (($(date +%s) > timeout)); then
+      echo -e '\nTimeout reached. Killing remaining processes...'
+      pkill --signal SIGKILL -u iobroker
+      echo 'Done.'
+      exit
+    fi
+
+    echo -n '.'
+    sleep 1
+  done
+
+  echo -e '\nDone.'
   exit
 }
 
diff --git a/debian/scripts/maintenance.sh b/debian/scripts/maintenance.sh
index 8b89fc7c..6b09c968 100644
--- a/debian/scripts/maintenance.sh
+++ b/debian/scripts/maintenance.sh
@@ -1,234 +1,228 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-############################
-##### default settings #####
-############################
+# bash strict mode
+set -euo pipefail
 
-autoconfirm=no              # could be set to true by commandline option
-killbyname=no               # could be set to true by commandline option / undocumented, only for use with backitup restore scripts
-
-####################################
-##### declaration of functions #####
-####################################
+autoconfirm=      # can be set to 'yes' by command line option
+killbyname=       # can be set to 'yes' by command line option (undocumented, only for use with backitup restore scripts)
+healthcheck=/opt/scripts/.docker_config/.healthcheck      # path of healthcheck file
+pkill_timeout=10      # timeout for stopping iobroker in seconds
 
 # display help text
 display_help() {
-  echo "This script is build to manage your ioBroker container!"
+  echo 'This script helps you manage your ioBroker container!'
   echo ''
   echo "Usage: maintenance [ COMMAND ] [ OPTION ]"
   echo "       maint [ COMMAND ] [ OPTION ]"
   echo "       m [ COMMAND ] [ OPTION ]"
   echo ''
-  echo "COMMANDS"
-  echo "------------------"
-  echo "       status     > reports the current state of maintenance mode"
-  echo "       on         > switches mantenance mode ON"
-  echo "       off        > switches mantenance mode OFF and shuts down or restarts container"
-  echo "       upgrade    > will put container to maintenance mode and upgrade ioBroker"
-  echo "       help       > shows this help"
+  echo 'COMMANDS'
+  echo '------------------'
+  echo '       status     > reports the current state of maintenance mode'
+  echo '       on         > switches mantenance mode ON'
+  echo '       off        > switches mantenance mode OFF and stops or restarts the container'
+  echo '       upgrade    > puts the container to maintenance mode and upgrades ioBroker'
+  echo '       help       > shows this help'
   echo ''
-  echo "OPTIONS"
-  echo "------------------"
-  echo "       -y|--yes   > confirms the used command without asking"
-  echo "       -h|--help  > shows this help"
+  echo 'OPTIONS'
+  echo '------------------'
+  echo '       -y|--yes   > confirms the used command without asking'
+  echo '       -h|--help  > shows this help'
   echo ''
-  exit 0
 }
 
-# checking maintenance mode status
-check_status() {
-  if [ $(cat /opt/scripts/.docker_config/.healthcheck) == 'maintenance' ]
-  then
+# check maintenance enabled
+maintenance_enabled() {
+  [[ -f "$healthcheck" && "$(cat "$healthcheck")" == maintenance ]]
+}
+
+# display maintenance status
+maintenance_status() {
+  if maintenance_enabled; then
     echo 'Maintenance mode is turned ON.'
-  elif [ $(cat /opt/scripts/.docker_config/.healthcheck) != 'maintenance' ]
-  then
+  else
     echo 'Maintenance mode is turned OFF.'
   fi
 }
 
-# turn maintenance mode ON
-switch_on() {
-  if [ $(cat /opt/scripts/.docker_config/.healthcheck) != 'maintenance' ] && [ "$killbyname" == "yes" ] # maintenance mode OFF / killbyname = yes  / undocumented, only for use with backitup restore scripts
-  then
+# enable maintenance mode
+enable_maintenance() {
+  if maintenance_enabled; then
+    echo 'Maintenance mode is already turned ON.'
+    return
+  fi
+
+  if [[ "$killbyname" == yes ]]; then
+    # undocumented option, only for use with backitup restore scripts
     echo 'This command will activate maintenance mode and stop js-controller.'
     echo 'Activating maintenance mode...'
-    echo "maintenance" > /opt/scripts/.docker_config/.healthcheck
-    sleep 1
-    echo 'Done.'
-    echo 'Stopping ioBroker...'
-    pkill -u iobroker -f iobroker.js-controller
+    echo 'maintenance' > "$healthcheck"
     sleep 1
     echo 'Done.'
-    exit 0
-  elif [ $(cat /opt/scripts/.docker_config/.healthcheck) != 'maintenance' ] && [ "$autoconfirm" == "no" ] # maintenance mode OFF / autoconfirm = no
-  then
-    echo 'You are now going to stop ioBroker and activating maintenance mode for this container.'
-    read -p 'Do you want to continue [yes/no]? ' A
-    if [ "$A" == "y" ] || [ "$A" == "Y" ] || [ "$A" == "yes" ]
-    then
-      echo 'Activating maintenance mode...'
-      echo "maintenance" > /opt/scripts/.docker_config/.healthcheck
-      sleep 1
-      echo 'Done.'
-      echo 'Stopping ioBroker...'
-      pkill -u iobroker
-      sleep 1
-      echo 'Done.'
-      exit 0
+    echo -n 'Stopping ioBroker...'
+    stop_iob
+    return
+  fi
+
+  echo 'You are now going to stop ioBroker and activate maintenance mode for this container.'
+
+  if [[ "$autoconfirm" != yes ]]; then
+    local reply
+
+    read -rp 'Do you want to continue [yes/no]? ' reply
+    if [[ "$reply" == y || "$reply" == Y || "$reply" == yes ]]; then
+      : # continue
     else
-    exit 0
+      return 1
     fi
-  elif [ $(cat /opt/scripts/.docker_config/.healthcheck) != 'maintenance' ] && [ "$autoconfirm" == "yes" ] # maintenance mode OFF / autoconfirm = yes
-  then
-    echo 'You are now going to stop ioBroker and activating maintenance mode for this container.'
-    echo 'This command was already confirmed by -y or --yes option.'
-    echo 'Activating maintenance mode...'
-    echo "maintenance" > /opt/scripts/.docker_config/.healthcheck
-    sleep 1
-    echo 'Done.'
-    echo 'Stopping ioBroker...'
-    pkill -u iobroker
-    sleep 1
-    echo 'Done.'
-    exit 0
   else
-    echo 'Maintenance mode is already turned ON.'
+    echo 'This command was already confirmed by the -y or --yes option.'
   fi
+
+  echo 'Activating maintenance mode...'
+  echo 'maintenance' > "$healthcheck"
+  sleep 1
+  echo 'Done.'
+  echo -n 'Stopping ioBroker...'
+  stop_iob
 }
 
-# turn maintenance mode OFF
-switch_off() {
-  if [ $(cat /opt/scripts/.docker_config/.healthcheck) == 'maintenance' ] && [ "$autoconfirm" == "no" ] # maintenance mode ON / autoconfirm = no
-  then
-    echo 'You are now going to deactivate maintenance mode for this container.'
-    echo 'Depending on the restart policy, your container will be stopped or restarted immediately.'
-    read -p 'Do you want to continue [yes/no]? ' A
-    if [ "$A" == "y" ] || [ "$A" == "Y" ] || [ "$A" == "yes" ]
-    then
-      echo 'Deactivating maintenance mode and forcing container to stop or restart...'
-      echo "stopping" > /opt/scripts/.docker_config/.healthcheck
-      pkill -u root
-      echo 'Done.'
-      exit 0
+# disable maintenance mode
+disable_maintenance() {
+  if ! maintenance_enabled; then
+    echo 'Maintenance mode is already turned OFF.'
+    return
+  fi
+
+  echo 'You are now going to deactivate maintenance mode for this container.'
+  echo 'Depending on the restart policy, your container will be stopped or restarted immediately.'
+
+  if [[ "$autoconfirm" != yes ]]; then
+    local reply
+
+    read -rp 'Do you want to continue [yes/no]? ' reply
+    if [[ "$reply" == y || "$reply" == Y || "$reply" == yes ]]; then
+      : # continue
     else
-      exit 0
+      return 1
     fi
-  elif [ $(cat /opt/scripts/.docker_config/.healthcheck) == 'maintenance' ] && [ "$autoconfirm" == "yes" ] # maintenance mode ON / autoconfirm = yes
-  then
-    echo 'You are now going to deactivate maintenance mode for this container.'
-    echo 'Depending on the restart policy, your container will be stopped or restarted immediately.'
-    echo 'This command was already confirmed by -y or --yes option.'
-    echo 'Deactivating maintenance mode and forcing container to stop or restart...'
-    echo "stopping" > /opt/scripts/.docker_config/.healthcheck
-    pkill -u root
-    echo 'Done.'
-    exit 0
   else
-    echo 'Maintenance mode is already turned OFF.'
+    echo 'This command was already confirmed by the -y or --yes option.'
   fi
+
+  echo 'Deactivating maintenance mode and forcing container to stop or restart...'
+  echo 'stopping' > "$healthcheck"
+  pkill -u root
+  echo 'Done.'
 }
 
 # upgrade js-controller
-upgrade() {
+upgrade_jscontroller() {
   echo 'You are now going to upgrade your js-controller.'
   echo 'As this will change data in /opt/iobroker, make sure you have a backup!'
-  echo 'During the upgrade process the container will automatically switch into maintenance mode and stop ioBroker.'
-  echo 'Depending of the restart policy, your container will be stopped or restarted automatically after the upgrade.'
-
-  if [ "$autoconfirm" == "no" ]
-  then
-    read -p 'Do you want to continue [yes/no]? ' A
-    if [ "$A" == "y" ] || [ "$A" == "Y" ] || [ "$A" == "yes" ]
-    then
-      : # Continue.
+  echo 'During the upgrade process, the container will automatically switch into maintenance mode and stop ioBroker.'
+  echo 'Depending on the restart policy, your container will be stopped or restarted automatically after the upgrade.'
+
+  if [[ "$autoconfirm" != yes ]]; then
+    local reply
+
+    read -rp 'Do you want to continue [yes/no]? ' reply
+    if [[ "$reply" == y || "$reply" == Y || "$reply" == yes ]]; then
+      : # continue
     else
-      exit 0
+      return 1
     fi
-  elif [ "$autoconfirm" == "yes" ]
-  then
-    echo 'This command was already confirmed by -y or --yes option.'
+  else
+    echo 'This command was already confirmed by the -y or --yes option.'
   fi
-  if [ $(cat /opt/scripts/.docker_config/.healthcheck) != 'maintenance' ]
-  then
-    echo 'Activating maintenance mode...'
-    echo "maintenance" > /opt/scripts/.docker_config/.healthcheck
-    sleep 1
-    echo 'Done.'  
-    echo 'Stopping ioBroker...'
-    pkill -u iobroker
-    sleep 5
-    echo 'Done.'
+
+  if ! maintenance_enabled > /dev/null; then
+    autoconfirm=yes
+    enable_maintenance
   fi
+
   echo 'Upgrading js-controller...'
   iobroker update
   sleep 1
   iobroker upgrade self
   sleep 1
   echo 'Done.'
+
   echo 'Container will be stopped or restarted in 5 seconds...'
   sleep 5
-  echo "stopping" > /opt/scripts/.docker_config/.healthcheck
+  echo 'stopping' > "$healthcheck"
   pkill -u root
-  exit 0
 }
 
-########################################
-##### parsing commands and options #####
-########################################
+# stop iobroker and wait until all processes stopped or pkill_timeout is reached
+stop_iob() {
+  local status timeout
 
-# reading all arguments and putting them in reverse
-reverse=
-for i in "$@"; do
-  reverse="$i $reverse"
-done
+  timeout="$(date --date="now + $pkill_timeout sec" +%s)"
+  pkill -u iobroker -f iobroker.js-controller
+  status=$?
+  if (( status >= 2 )); then      # syntax error or fatal error
+    return 1
+  fi
 
-# checking the arguments
-for i in $reverse; do
-  case $i in
+  if (( status == 1 )); then      # no processes matched
+    return
+  fi
+
+  # pgrep exits with status 1 when there are no matches
+  while pgrep -u iobroker > /dev/null; (( $? != 1 )); do
+    if (($(date +%s) > timeout)); then
+      echo -e '\nTimeout reached. Killing remaining processes...'
+      pgrep --list-full -u iobroker
+      pkill --signal SIGKILL -u iobroker
+      echo 'Done.'
+      return
+    fi
+
+    echo -n '.'
+    sleep 1
+  done
+
+  echo -e '\nDone.'
+}
+
+# parsing commands and options
+
+# default command to run unless another was given
+run=(display_help)
+
+for arg in "$@"; do
+  case $arg in
     help|-h|--help)
-      display_help        # calling function to display help text
-      break
+      run=(display_help)
       ;;
     status)
-      check_status        # calling function to check maintenance mode status
-      break
+      run=(maintenance_status)
       ;;
     on)
-      switch_on           # calling function to switch maintenance mode on
-      break
+      run=(enable_maintenance)
       ;;
     off)
-      switch_off          # calling function to switch maintenance mode off
-      break
+      run=(disable_maintenance)
       ;;
     upgrade)
-      upgrade             # calling function to upgrade js-controller
-      break
+      run=(upgrade_jscontroller)
       ;;
     -y|--yes)
-      autoconfirm=yes     # setting autoconfrm option to "yes"
-      shift
+      autoconfirm=yes
       ;;
     -kbn|--killbyname)
-      killbyname=yes     # setting killbyname option to "yes"
-      shift
+      killbyname=yes
       ;;
-    -a=*|--argument=*)    # dummy exaple for parsing option with value
-      ARGUMENT="${i#*=}"
-      shift
-      ;;
-    --)                   # End of all options.
-      shift
-      break
-      ;;
-    -?*|?*)
-      echo 'WARN: Unknown parameter. Please try again or see help (-h|--help).'
+    --)
       break
       ;;
-    *)                    # Default case: No more options, so break out of the loop.
-      break
+    *)
+      >&2 echo "Unknown parameter: $arg"
+      >&2 echo 'Please try again or see help (help|-h|--help).'
+      exit 1
       ;;
   esac
 done
 
-exit 0
+"${run[@]}"
\ No newline at end of file