diff --git a/contrib/Nagios/mars.rules b/contrib/Nagios/mars.rules
new file mode 100644
index 00000000..307f4699
--- /dev/null
+++ b/contrib/Nagios/mars.rules
@@ -0,0 +1,65 @@
+# Config file for mars_check.sh
+#
+# This file is part of MARS project: http://schoebel.github.io/mars/
+#
+# Copyright (C) 2015 Thomas Schoebel-Theuer
+# Copyright (C) 2015 1&1 Internet AG
+#
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without any warranty.
+
+
+# For each variable $Var (as documented in "mars_check.sh --help"), the following relatives are always defined:
+#
+# $LastVar           the old value from the last run of mars_check.sh (whenever it was called; recommendation: 5 minutes)
+# $DeltaLastVar      the difference between $Var and $LastVar
+# $RateLastVar       the $DeltaLastVar normalized to the elapsed time (unit: per minutes)
+#
+# $MediumVar         the old value from a medium-term run of mars_check.sh ($window_medium, default 3600s)
+# $DeltaMediumVar    the difference between $Var and $MediumVar
+# $RateMediumVar     the $DeltaMediumVar normalized to the elapsed time (unit: per minutes)
+#
+# $LongtermVar       the old value from a longterm run of mars_check.sh ($window_longterm, default 24h)
+# $DeltaLongtermVar  the difference between $Var and $LongtermVar
+# $RateLongtermVar   the $DeltaLongtermVar normalized to the elapsed time (unit: per minutes)
+
+
+# The first number in each line is the priority class.
+# Lower number = higher priority = takes precence over higher class numbers
+# Exception: 0 means that the check will appear unconditionally (class is irrelevant)
+#
+# Hint: checks can be simply disabled by commenting them out
+
+
+#####################################################################################
+# List of global checks
+
+1 ModuleLoaded <= 0             CRITICAL: mars module is not loaded
+2 Responsive <= 0               CRITICAL: mars_light thread is not responsive / possibly hanging
+5 SpaceRest <= 4                CRITICAL: only $SpaceRest GiB left on /mars/
+6 SpacePercent >= 70            CRITICAL: Used space on /mars/ is $SpacePercent %
+7 SpacePercent >= 30            WARNING: Used space on /mars/ is $SpacePercent %
+
+#####################################################################################
+# List of local checks = per resource. The resource name can be substituted via $res
+
+# all hosts
+10 AliveAge >= 300               CRITICAL: resource $res: primary host ${Designated[$res]} is not reachable for $AliveAge seconds
+11 Alive <= 0                    WARNING: resource $res: primary host ${Designated[$res]} is not reachable
+12 Emergency >= 1                CRITICAL: resource $res is in emergency mode, too less space on /mars/
+13 SplitBrain >= 1               CRITICAL: split brain on $res detected
+
+# only secondaries
+30 Sync <= 0                     WARNING: resource $res sync is switched off
+31 Fetch <= 0                    WARNING: resource $res fetch is switched off
+32 Replay <= 0                   WARNING: resource $res replay is switched off
+
+40 SyncRest >= 999999            WARNING: resource $res SyncRest=${SyncRest[$res]} is too large
+41 FetchRest >= 999999           WARNING: resource $res FetchRest=${FetchRest[$res]} is too large
+42 ReplayRest >= 999999          WARNING: resource $res ReplayRest=${ReplayRest[$res]} is too large
+
+50 DeltaLastSyncRest <= 99999   && SyncRest >= 1     WARNING: resource $res SyncRest=${SyncRest[$res]} sync has stopped
+51 DeltaLastFetchRest <= 99999  && FetchRest >= 1    WARNING: resource $res FetchRest=${FetchRest[$res]} fetch has stopped
+52 DeltaLastReplayRest <= 99999 && ReplayRest >= 1   WARNING: resource $res ReplayRest=${ReplayRest[$res]} replay has stopped
diff --git a/contrib/Nagios/mars_check.sh b/contrib/Nagios/mars_check.sh
new file mode 100755
index 00000000..9d28fba3
--- /dev/null
+++ b/contrib/Nagios/mars_check.sh
@@ -0,0 +1,450 @@
+#!/bin/bash
+#
+# This file is part of MARS project: http://schoebel.github.io/mars/
+#
+# Copyright (C) 2015 Thomas Schoebel-Theuer
+# Copyright (C) 2015 1&1 Internet AG
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+#
+# Nagios check, respecting debian package settings
+#
+# TST spring 2015 lab prototype
+#
+# Verbose mode and options / help is not yet supported.
+
+#set -e
+orig_vars="$(set | grep '^[_A-Za-z0-9]\+=' | cut -d= -f1)"
+
+# Config file for defaults.
+# May be used for hard override of the following definitions.
+default_file="${default_file:-/etc/default/mars}"
+
+# Defaults for configuration variables
+service="${service:-MARS}"
+check_enable=${check_enable:-1}
+alive_window=${alive_window:-120} # seconds
+responsive_window=${responsive_window:-600} # seconds
+class_mode=${class_mode:-1}
+warnings=${warnings:-0}
+simulate=${simulate:-0}
+verbose=${verbose:-0}
+help=${help:-0}
+
+mars_dir="${mars_dir:-/mars}"
+config_dir="${config_dir:-/etc/mars}"
+config_file="${config_file:-mars.rules}"
+statusfile_dir="${statusfile_dir:-/var/cache/mars}"
+status_last="${status_last:-$statusfile_dir/last.status}"
+status_medium="${status_medium:-$statusfile_dir/medium.status}"
+status_longterm="${status_long:-$statusfile_dir/longterm.status}"
+window_medium=${window_medium:-3600}
+window_longterm=${window_longterm:-$(( 3600 * 24 ))}
+
+# Enable this script by default
+ENABLED="true"
+
+param_vars="$(set | grep '^[_A-Za-z0-9]\+=' | cut -d= -f1)"
+
+# Derived from the defaults
+file_list="./$config_file $config_dir/$config_file"
+
+# Nagios Exit Codes
+OK=0
+WARNING=1
+CRITICAL=2
+UNKNOWN=3
+
+function abort
+{
+    local msg="$1"
+    echo "$service Unknown: $msg"
+    exit $UNKNOWN
+}
+
+function source_when_possible
+{
+    local file="$1"
+    local type="$2"
+
+    if [[ -r "$file" ]]; then
+	. "$file" || abort "$type file $file is not parsable"
+    fi
+}
+
+source_when_possible "$default_file" "config"
+
+# Allow forceful override of any _known_ variable at the command line
+for i; do
+    if [[ "$i" =~ ^--[-_A-Za-z0-9]+$ ]]; then
+	param="${i#--}"
+	var="${param//-/_}"
+        [[ "$(eval "echo \"\$$var\"")" = "" ]] && abort "Variable '$var' is unknown"
+	eval "$var=1"
+    elif [[ "$i" =~ ^--[-_A-Za-z0-9]+= ]]; then
+	param="${i#--}"
+	var="${param%%=*}"
+	var="${var//-/_}"
+	val="${param#*=}"
+        [[ "$(eval "echo \"\$$var\"")" = "" ]] && abort "Variable '$var' is unknown"
+	eval "$var=$val"
+    elif [[ "$i" =~ ^-h$ ]]; then
+	help=1
+    elif [[ "$i" =~ ^-v$ ]]; then
+	(( verbose++ ))
+    else
+	abort "bad parameter syntax '$i'"
+    fi
+done
+
+# Almost silently exit if not enabled
+if (( !check_enable)) || [[ "$ENABLED" != "true" ]] && (( !help )); then
+    echo "${service}_IS_DISABLED OK"
+    exit $OK
+fi
+
+########################
+# Prepare Variables
+
+var_list="ListOfPrimary ListOfNotYetPrimary ListOfRemainsPrimary ListOfSecondary ListOfAny"
+val_list="ElapsedLast ElapsedMedium ElapsedLongterm ModuleLoaded Responsive SpacePercent SpaceRest"
+array_list="SplitBrain Designated Alive AliveAge Sync Fetch Replay SyncRest FetchRest ReplayRest Emergency"
+
+start_vars="$(set | grep '^[_A-Za-z0-9]\+=' | cut -d= -f1)"
+
+for i in $var_list $val_list; do
+    eval "$i=''"
+    for age in Last Medium Longterm; do
+	eval "$age$i=''"
+    done
+done
+
+for i in $array_list; do
+    eval "declare -A $i"
+    for age in Last Medium Longterm; do
+	eval "declare -A $age$i"
+    done
+done
+
+basic_vars="$(set | grep '^[_A-Za-z0-9]\+=' | cut -d= -f1)"
+
+########################
+# Help text
+
+if (( help )); then
+    all_vars="$(set | grep '^[_A-Za-z0-9]\+=' | cut -d= -f1 | sort)"
+    cat<<EOF
+Nagios-compatible plugin for service $service
+
+Usage: $0 [-h] {-v} {--<switch>} {--<var>=<value>}
+
+The following parameter variables can be either passed by the
+environment, or used for hard overrinding on the command line:
+
+$(
+    declare -A orig
+    for i in $orig_vars; do
+	orig[$i]=1
+    done
+    declare -A param
+    for i in $param_vars; do
+	param[$i]=1
+    done
+    for i in $all_vars; do
+	[[ "$i" =~ _vars$ ]] && continue
+	if (( param[$i] && !orig[$i] )); then
+	    echo "$i=$(eval "echo \${$i}")"
+	fi
+    done
+)
+
+The following CamelCase basic variables may be used in one of the
+rules files $file_list:
+
+$(
+    declare -A start
+    for i in $start_vars; do
+	start[$i]=1
+    done
+    declare -A basic
+    for i in $basic_vars; do
+	basic[$i]=1
+    done
+    for i in $all_vars; do
+	[[ "$i" =~ _vars$ ]] && continue
+	if (( basic[$i] && !start[$i] )); then
+	    keys="$(eval echo "\${!$i[@]}")"
+	    if [[ "$keys" != "0" ]]; then
+		echo "${i}[\$res]"
+	    else
+		echo "$i"
+	    fi
+	fi
+    done
+)
+EOF
+    exit 0
+fi
+
+########################
+# Read in old status files
+
+source_when_possible "$status_last" "last status"
+source_when_possible "$status_medium" "medium-term status"
+source_when_possible "$status_longterm" "longterm status"
+
+marsadm=${marsadm:-$(which marsadm)}
+# exit if marsadm is not found
+command -v $marsadm > /dev/null || abort "Command marsadm '$marsadm' is not installed"
+
+########################
+# get Global variables
+
+ElapsedLast=$(( $(date +%s) - $(stat --printf="%Y" $status_last 2> /dev/null || echo "0") ))
+ElapsedMedium=$(( $(date +%s) - $(stat --printf="%Y" $status_medium 2> /dev/null || echo "0") ))
+ElapsedLongterm=$(( $(date +%s) - $(stat --printf="%Y" $status_longterm 2> /dev/null || echo "0") ))
+
+ModuleLoaded="$( [[ -d /prco/sys/mars ]]; echo $? )"
+
+Responsive="$($marsadm --macro="%is-alive{%{host}}" --window=$responsive_window view 2> /dev/null)"
+
+SpacePercent="$(df $mars_dir | grep -o "[0-9]\%" | tail -1 | sed 's/\%//g' 2> /dev/null)"
+
+SpaceRest="$($marsadm view-rest-space 2> /dev/null)"
+
+# get a list of Primary and Secondary resource names
+# don't run the while loop in a subshell, use the main shell
+while read dashes txt res; do
+    read role
+    eval "ListOf$role+=' $res'"
+    eval "ListOfAny+=' $res'"
+done <<EOF 2> /dev/null
+$($marsadm view-role all 2> /dev/null)
+EOF
+
+########################
+# get Resource variables
+
+for i in $ListOfAny; do
+    SplitBrain[$i]="$($marsadm view-is-split-brain $i 2> /dev/null)"
+    Emergency[$i]="$($marsadm view-is-emergency $i < /dev/null 2> /dev/null)"
+done
+
+for i in $ListOfPrimary; do
+    : #echo "Pri '$i'"
+done
+
+for i in $ListOfSecondary; do
+    Designated[$i]="$($marsadm view-get-primary $i 2> /dev/null)"
+    Alive[$i]="$($marsadm --macro="%is-alive{${Designated[$i]}}" --window=$alive_window view $i 2> /dev/null)"
+    AliveAge[$i]="$($marsadm view-alive-age $i 2> /dev/null)"
+    Sync[$i]="$($marsadm view-todo-sync $i 2> /dev/null)"
+    Fetch[$i]="$($marsadm view-todo-fetch $i 2> /dev/null)"
+    Replay[$i]="$($marsadm view-todo-replay $i 2> /dev/null)"
+    SyncRest[$i]="$($marsadm view-sync-rest $i 2> /dev/null)"
+    FetchRest[$i]="$($marsadm view-fetch-rest $i 2> /dev/null)"
+    ReplayRest[$i]="$($marsadm view-replay-rest $i 2> /dev/null)"
+done
+
+
+########################
+# compute Delta variables (when possible)
+
+for i in $val_list; do
+    for age in Last Medium Longterm; do
+	if [[ "$(eval echo "\${$age$i}")" != "" ]]; then
+	    declare Delta$age$i
+	    eval "Delta$age$i=$(( $(eval echo "\${$i}") - $(eval echo "\${$age$i}") ))"
+	    declare Rate$age$i
+	    eval "Rate$age$i=$(( $(eval echo "\${Delta$age$i}") * 60 / Elapsed${age} ))"
+	fi
+    done
+done
+for i in $array_list; do
+    for j in $(eval echo "\${!$i[*]}"); do
+	for age in Last Medium Longterm; do
+	    if [[ "$(eval echo "\${$age$i[$j]}")" != "" ]]; then
+		declare -A Delta$age$i[$j]
+		eval "Delta$age$i[$j]=$(( $(eval echo "\${$i[$j]}") - $(eval echo "\${$age$i[$j]}") ))"
+		declare -A Rate$age$i[$j]
+		eval "Rate$age$i[$j]=$(( $(eval echo "\${Delta$age$i[$j]}") * 60 / Elapsed${age} ))"
+	    fi
+	done
+    done
+done
+
+########################
+# Write out new status file
+
+mkdir -p "$statusfile_dir"
+(
+    for i in $var_list $val_list; do
+	echo "Last$i='$(eval echo "\${$i}")'"
+    done
+    
+    for i in $array_list; do
+	for j in $(eval echo "\${!$i[*]}"); do
+	    echo "Last$i[$j]='$(eval echo "\${$i[$j]}")'"
+	done
+    done
+) > "${status_last}.tmp" && \
+    mv "${status_last}.tmp" "${status_last}" && \
+    if ! [[ -r $status_medium.tmp ]] || (( $(stat --printf="%Y" $status_medium.tmp) < $(stat --printf="%Y" $status_last) - ( $window_medium / 2 ) )); then
+    mv -f $status_medium.tmp $status_medium 2> /dev/null || true
+    sed 's/^Last/Medium/' < $status_last > $status_medium.tmp2 && \
+	mv $status_medium.tmp2 $status_medium.tmp
+fi &&\
+    if ! [[ -r $status_longterm.tmp ]] || (( $(stat --printf="%Y" $status_longterm.tmp) < $(stat --printf="%Y" $status_last) - ( $window_longterm / 2 ) )); then
+    mv -f $status_longterm.tmp $status_longterm 2> /dev/null || true
+    sed 's/^Last/Longterm/' < $status_last > $status_longterm.tmp2 && \
+	mv $status_longterm.tmp2 $status_longterm.tmp
+fi
+
+########################
+# Output Handling
+
+code_max=0
+
+# this can be called multiple times.
+# it remembers the maximum error level in $code_max
+function do_check
+{
+    local class="$1"
+    local key="$2"
+
+    local file
+    local rule_var
+    local rule_op
+    local rule_val
+    local rule_txt
+    local found_count=0
+    local matches=0
+
+    for file in $file_list; do
+	if [[ -r "$file" ]]; then
+	    while read rule_class rule_var rule_op rule_val rule_txt; do
+		if [[ "$rule_var" = "$key" ]]; then
+		    (( ++found_count ))
+		    (( rule_class != class && class_mode )) && continue
+		    local keys="$(eval echo "\${!$rule_var[@]}")"
+		    if [[ "$keys" != "" ]] && [[ "$keys" != "0" ]]; then
+			local res
+			for res in $keys; do
+			    if [[ "$(eval echo "\${$rule_var[$res]}")" != "" ]]; then
+				while (( $rule_var[$res] $rule_op $rule_val || simulate )); do
+				    (( ++matches ))
+				    if [[ "$rule_txt" =~ "&&" ]]; then
+					read dummy rule_var rule_op rule_val rule_txt <<< "$rule_txt"
+				    else
+					_out_txt "$rule_txt" "$res"
+					break
+				    fi
+				done
+			    else
+				(( warnings )) && echo "Undefined variable '$rule_var[$res]'" >> /dev/stderr
+			    fi
+			done
+		    else
+			if [[ "$(eval echo "\${$rule_var}")" != "" ]]; then
+			    while (( $rule_var $rule_op $rule_val || simulate )); do
+				(( ++matches ))
+				if [[ "$rule_txt" =~ "&&" ]]; then
+				    read dummy rule_var rule_op rule_val rule_txt <<< "$rule_txt"
+				else
+				    _out_txt "$rule_txt" "UNDEF"
+				    break
+				fi
+			    done
+			else
+			    (( warnings )) && echo "Undefined variable '$rule_var'" >> /dev/stderr
+			fi
+		    fi
+		fi
+	    done <<EOF
+$(grep -v '^#' $file | grep -v '^\s*$')
+EOF
+	fi
+    done
+    if (( warnings && !found_count )); then
+	echo "Cannot find key '$key' in $config_file $config_dir/$config_file" >> /dev/stderr
+    fi
+    return 0
+}
+
+function _out_txt
+{
+    local txt="$1"
+    local res="$2"
+
+    txt="$(echo "$txt" | sed 's/\${/\\\${/g')"
+    # eval down (fixedpoint iteration)
+    local old=""
+    while [[ "$txt" != "$old" ]]; do
+	old="$txt"
+	txt="$(eval echo "$txt")"
+    done
+    echo "$service $txt"
+
+    local this_code=0
+    echo "$txt" | grep -i -q "WARNING" && this_code=1
+    echo "$txt" | grep -i -q "CRITICAL" && this_code=2
+    (( this_code > code_max )) && code_max=$this_code
+    return 0
+}
+
+########################
+# Main program
+
+class_list="$(cat $file_list 2>/dev/null | grep -v '^#' | grep -v '^\s*$' | cut -d" " -f1 | sort -n -u)"
+
+for class in $class_list; do
+    ########################
+    # Global checks
+
+    do_check "$class" ModuleLoaded
+    do_check "$class" Responsive
+    do_check "$class" SpacePercent
+    do_check "$class" SpaceRest
+
+    ########################
+    # Resource checks
+
+    do_check "$class" Alive
+    do_check "$class" AliveAge
+    do_check "$class" Emergency
+    do_check "$class" SplitBrain
+    for i in $ListOfSecondary; do
+	do_check "$class" Sync
+	do_check "$class" Fetch
+	do_check "$class" Replay
+	do_check "$class" SyncRest
+	do_check "$class" FetchRest
+	do_check "$class" ReplayRest
+	for age in Last Medium Longterm; do
+	    do_check "$class" Delta${age}SyncRest
+	    do_check "$class" Delta${age}FetchRest
+	    do_check "$class" Delta${age}ReplayRest
+	done
+    done
+    (( !class_mode )) && break
+    (( class > 0 && code_max > 0 )) && break
+done
+
+if (( !code_max )); then
+    echo "$service OK"
+fi
+exit $code_max