nagios 监控xenserver memery

cat check_xen_mem.sh
#!/bin/sh

function usage()
{
msg="$0 : use to check xenserver memery usage for nagios"
echo "****************************************************"
echo -e "\033[1;94m${msg}\033[0m"
echo -e "Usage:"
echo -e "       $0 [-w warning -c critical]"
echo -e "       $0 -w 80 -c 90 "
echo "****************************************************"
}

if [ $# -eq 0 ];then
warning=0.85
critical=0.95
elif [ "$1" = "-w" ];then
warning=`echo $2`
shift
shift
if [ "$1" != "-c" ];then
usage
exit 1
fi
critical=`echo $2`
shift
shift
else
usage
exit 1
fi

STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3

uuid_list=`xe host-list | grep uuid | awk '{print $5}'`
i=1
for uuid in $uuid_list
do
each_mem_total[$i]=`xe host-param-get param-name=memory-total uuid=$uuid`
each_mem_free[$i]=`xe host-param-get param-name=memory-free uuid=$uuid`
let i=i+1
done

mem_total=`echo ${each_mem_total[@]} | awk '{for(i=0;i<NF;i++) total+=$i; print total/1024/1024/1024}'`
mem_free=`echo ${each_mem_free[@]} | awk '{for(i=0;i<NF;i++) free+=$i;print free/1024/1024/1024}'`
#mem_usage=$(((mem_total-mem_free)/mem_total))
mem_usage=`awk -v a=$mem_total -v b=$mem_free 'BEGIN{printf "%.2f",(a-b)/a }'`
host_num=${#each_mem_total[@]}

performance="$host_num host; usage: $mem_usage; free: $mem_free | mem_usage=$mem_usage;$warning;$critical;0;100;mem_free=$mem_free;;;;;"

function cmp_data(){
if [ $1 \< $2 ];then
echo "OK $performance"
exit_code=$STATE_OK
elif [ $1 \> $3 ];then
echo "CRITICAL $performance"
exit_code=$STATE_CRITICAL
else
echo "WARNING $performance"
exit_code=$STATE_WARNING
fi
}

cmp_data $mem_usage $warning $critical
exit $exit_code