check_mem

#!/usr/bin/env bash
#
# Check for high memory usage on an Illumos
# based machine
#
# Not typically a problem in itself, but can
# indicate future problems
#
# Author: Dave Eddy <dave@voxer.com>
# Creation Date: 9/14/2012
# 01/10/2014 Added check for global zone (Napsty)
# License: MIT

rss_and_cap() {
	local name value
	if [[ $(zonename) == 'global' ]]; then
		local pagesize=$(pagesize)
		while read name value; do
			IFS=: read _ _ _ name <<< "$name"
			local "$name"
			read "$name" <<< "$value"
		done < <(kstat -p unix::system_pages:{availrmem,freemem,physmem})
		echo "$(((availrmem - freemem) * pagesize)) $((physmem * pagesize))"
	else
		while read name value; do
			IFS=: read _ _ _ name <<< "$name"
			local "$name"
			read "$name" <<< "$value"
		done < <(kstat -pc zone_memory_cap :::rss :::physcap)
		echo "$rss $physcap"
	fi
}

warning=90
critical=95
perfdata=true
while getopts 'nw:c:' option; do
	case "$option" in
		n) perfdata=false;;
		w) warning=$OPTARG;;
		c) critical=$OPTARG;;
	esac
done

read rss cap < <(rss_and_cap)
perc_used=$((rss * 100 / cap))

if [[ -z $perc_used ]]; then
	echo 'unknown: error retrieving data'
	exit 3
elif ((perc_used >= critical)); then
	echo -n 'critical: '
	ret=2
elif ((perc_used >= warning)); then
	echo -n 'warning: '
	ret=1
else
	echo -n 'ok: '
	ret=0
fi

echo -n "$perc_used% used (warning=$warning%, critical=$critical%)"
$perfdata && echo "|mem_used=$rss;mem_cap=$cap" || echo
exit "$ret"