Check mem (by Nestor@Toronto)

This is a great script that various people have improved. I've been using a forked version on github for some years. We recently improved it to use '/proc/meminfo' output so it its less brittle to changes in 'free' output. So it works with almost all Linux releases/versions. Small improvements to the chart also. https://github.com/whereisaaron/linux-check-mem-nagios-plugin

Hi, Here is a modification for more accurate results on CentOS/RHEL 6.x. This changes the memUsed_m variable to use a custom calculation instead of just using the Used number from free -m. This is similar to what the other reviewer did for 7.x systems. It uses the number from memTotal_m and then subtracts memFree_m, memBuffer_m, and memCache_m to come up with memUsed_m. You need to comment the original memUsed_m line then add a line after memCache_m as shown: memTotal_m=`echo "$FreeM" |grep Mem |awk '{print $2}'` # Comment This Line #memUsed_m=`echo "$FreeM" |grep Mem |awk '{print $3}'` memFree_m=`echo "$FreeM" |grep Mem |awk '{print $4}'` memBuffer_m=`echo "$FreeM" |grep Mem |awk '{print $6}'` memCache_m=`echo "$FreeM" |grep Mem |awk '{print $7}'` #Add the following line: memUsed_m=$(($memTotal_m-$memFree_m-$memBuffer_m-$memCache_m)) memUsedPrc=`echo $((($memUsed_m*100)/$memTotal_m))||cut -d. -f1` Thanks for the great plugin!

Centos 7 Free command output changed a bit, plus I would count cached memory as free. #!/bin/bash if [ "$1" = "-w" ] && [ "$2" -gt "0" ] && [ "$3" = "-c" ] && [ "$4" -gt "0" ]; then FreeM=`free -m` memTotal_m=`echo "$FreeM" |grep Mem |awk '{print $2}'` memUsed_m=`echo "$FreeM" |grep Mem |awk '{print $3}'` memFree_m=`echo "$FreeM" |grep Mem |awk '{print $4}'` memBuffer_cache_m=`echo "$FreeM" |grep Mem |awk '{print $6}'` memAvailable_m=`echo "$FreeM" |grep Mem |awk '{print $7}'` memUsed_m=$(($memTotal_m-$memFree_m-$memBuffer_cache_m)) memUsedPrc=`echo $((($memUsed_m*100)/$memTotal_m))||cut -d. -f1` if [ "$memUsedPrc" -ge "$4" ]; then echo "Memory: CRITICAL Total: $memTotal_m MB - Used: $memUsed_m MB - $memUsedPrc% used!|TOTAL=$memTotal_m;;;; USED=$memUsed_m;;;; BUFFER/CACHE=$memBuffer_cache_m;;;; AVAILABLE=$memAvailable_m;;;;" exit 2 elif [ "$memUsedPrc" -ge "$2" ]; then echo "Memory: WARNING Total: $memTotal_m MB - Used: $memUsed_m MB - $memUsedPrc% used!|TOTAL=$memTotal_m;;;; USED=$memUsed_m;;;; BUFFER/CACHE=$memBuffer_cache_m;;;; AVAILABLE=$memAvailable_m;;;;" exit 1 else echo "Memory: OK Total: $memTotal_m MB - Used: $memUsed_m MB - $memUsedPrc% used|TOTAL=$memTotal_m;;;; USED=$memUsed_m;;;; BUFFER/CACHE=$memBuffer_cache_m;;;; AVAILABLE=$memAvailable_m;;;;" exit 0 fi else # If inputs are not as expected, print help. sName="`echo $0|awk -F '/' '{print $NF}'`" echo -e "nntt### $sName Version 2.1###n" echo -e "# Usage:t$sName -w -c " echo -e "tt= warnlevel and critlevel is percentage value without %n" echo "# EXAMPLE:t/usr/lib64/nagios/plugins/$sName -w 80 -c 90" echo -e "nCopyright (C) 2012 Lukasz Gogolin (lukasz.gogolin@gmail.com), improved by Nestor 2015nn" exit fi