Jester

#!/bin/bash
#%# family=auto
#%# capabilities=autoconf suggest

if [ "$1" = "autoconf" ]; then
        echo yes
        exit 0
fi

if [ "$1" = "suggest" ]; then
    while read -a line
    do
        if [[ "${line[2]}" =~ "^[hs]d[a-z][0-9]*\$" ]]
        then
            echo "${line[2]}"
        fi
    done < /proc/diskstats
    exit 0
fi

device=$(basename $0)
device=${device#diskutil_}
if [ "$1" = "config" ]; then
        echo 'graph_category disk'
        echo "graph_title Disk utilization for /dev/${device}"
        echo 'graph_args -l 0 -u 100'
        echo 'graph_vlabel %'
        echo 'util.label utilization'
        echo 'util.info utilization %'
        echo 'util.type GAUGE'
        echo 'util.draw AREA'
        exit 0
fi

statefiledir=/var/lib/munin/plugin-state/
statefile="${statefiledir}diskutil-${device}.state"

ncpu=0
while read -a line
do
    if [[ "${line[0]}" == "cpu" ]]
    then
        newticks=$(( line[1] + line[2] + line[3] + line[4] + line[5] + line[6] + line[7] + line[8] + line[9] ))
    elif [[ "${line[0]}" =~ "cpu" ]]
    then
        ncpu=$((ncpu + 1))
    else
        break
    fi
done < /proc/stat

while read -a line
do
    if [[ "${line[2]}" = "$device" ]]
    then
        newioticks=${line[12]}
    fi
done < /proc/diskstats

if [ -s $statefile ] ; then
        read oldticks oldioticks <$statefile
else
        oldticks=$newticks
        oldioticks=$newioticks
fi
echo "${newticks} ${newioticks}" > $statefile

deltaticks=$(($newticks-$oldticks))
deltaioticks=$(($newioticks-$oldioticks))

printf "util.value %d.%d\n" $(($deltaioticks*$ncpu*10/$deltaticks)) $(($deltaioticks*$ncpu*10*10000/$deltaticks-$deltaioticks*$ncpu*10/$deltaticks*10000))