check diskspace availability of zfs with nrpe

check_zfs

#!/bin/sh

# Nagios plugin return values
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3

# do we have what we need
if [ ${#} -lt 1 ] ; then
    exit ${STATE_UNKNOWN}
fi

DATASET="${1}"
WARNING="${2:-20}"
CRITICAL="${3:-10}"

# is warning bigger then critical?
if [ ${WARNING} -le ${CRITICAL} ] ; then
    echo "Warning[${WARNING}%] must be bigger than Critical[${CRITICAL}%]"
    exit ${STATE_UNKNOWN}
fi

#
LINE=$(/sbin/zfs list -oavail,used -t filesystem -pH "${DATASET}")

AVAIL="$(echo "${LINE}" | awk '{print $1}')"
USED="$(echo "${LINE}" | awk '{print $2}')"

TOTAL=$((AVAIL+USED))

FREEPERC=$(bc -l <<EOC
scale=0
${AVAIL}*100/${TOTAL}
EOC
)

if [ "${FREEPERC}" -gt "${WARNING}" ]; then
        exit ${STATE_OK}
else 
    if [ "${FREEPERC}" -gt "${CRITICAL}" ]; then
        exit ${STATE_WARNING}
    else
        exit ${STATE_CRITICAL}
    fi
fi