#!/bin/sh

# Copyright (c) 2011, Jochen Bern
# taken from:
# http://www.monitoring-portal.org/wbb/index.php?page=Thread&postID=152833#post152833

SLEEP="${2:-5}"

if [ "$1" = "" ]; then
   echo "Which disk/partition, please?"
   exit 3
fi
if [ "`uname -s`" != "Linux" ]; then
    if [ "`uname -r | sed -e 's/^\(....\).*/\1/'`" != "2.6." -a "`uname -r | sed -e 's/^\(..\).*/\1/'`" != "3." ]; then
        echo "CRITICAL: I need a >= 2.6 Linux kernel's /proc/diskstats to parse"
        exit 3
    fi
fi

PERFDATA="rate_interval=${SLEEP}s"

READOPS=0
READSEC=0
READTIM=0
WRITEOPS=0
WRITESEC=0
WRITETIM=0
IOCNT=0
IOTIM=0

MODE="abs_"
DIVIDER=1

ONELINE=`awk '{ if ($3=="'"$1"'") print; }' /proc/diskstats`

if [ "$ONELINE" = "" ]; then
   echo "CRITICAL: Cannot find disk/partition $1 in /proc/diskstats"
   exit 2
fi

PERFDATA="$PERFDATA ${MODE}total_reads=`echo $ONELINE | awk '{ printf "%u",($4-'$READOPS')/'$DIVIDER'; }'`"
READOPS=`echo $ONELINE | awk '{ printf "%u",$4; }'`
PERFDATA="$PERFDATA ${MODE}sector_reads=`echo $ONELINE | awk '{ printf "%u",($6-'$READSEC')/'$DIVIDER'; }'`"
READSEC=`echo $ONELINE | awk '{ printf "%u",$6; }'`
PERFDATA="$PERFDATA ${MODE}time_reads=`echo $ONELINE | awk '{ printf "%u",($7-'$READTIM')/'$DIVIDER'; }'`ms"
READTIM=`echo $ONELINE | awk '{ printf "%u",$7; }'`
PERFDATA="$PERFDATA ${MODE}total_writes=`echo $ONELINE | awk '{ printf "%u",($8-'$WRITEOPS')/'$DIVIDER'; }'`"
WRITEOPS=`echo $ONELINE | awk '{ printf "%u",$8; }'`
PERFDATA="$PERFDATA ${MODE}sector_writes=`echo $ONELINE | awk '{ printf "%u",($10-'$WRITESEC')/'$DIVIDER'; }'`"
WRITESEC=`echo $ONELINE | awk '{ printf "%u",$10; }'`
PERFDATA="$PERFDATA ${MODE}time_writes=`echo $ONELINE | awk '{ printf "%u",($11-'$WRITETIM')/'$DIVIDER'; }'`ms"
WRITETIM=`echo $ONELINE | awk '{ printf "%u",$11; }'`
PERFDATA="$PERFDATA ${MODE}curr_io=`echo $ONELINE | awk '{ printf "%u",($12-'$IOCNT')/'$DIVIDER'; }'`"
IOCNT=`echo $ONELINE | awk '{ printf "%u",$12; }'`
PERFDATA="$PERFDATA ${MODE}time_io=`echo $ONELINE | awk '{ printf "%u",($13-'$IOTIM')/'$DIVIDER'; }'`ms"
IOTIM=`echo $ONELINE | awk '{ printf "%u",$13; }'`

#echo "DEBUG: time_reads $READTIM time_writes $WRITETIM time_io $IOTIM"

sleep $SLEEP

MODE="rate_"
DIVIDER=$SLEEP

ONELINE=`awk '{ if ($3=="'"$1"'") print; }' /proc/diskstats`

PERFDATA="$PERFDATA ${MODE}total_reads=`echo $ONELINE | awk '{ printf "%f",($4-'$READOPS')/'$DIVIDER'; }'`"
READOPS=`echo $ONELINE | awk '{ printf "%f",$4; }'`
PERFDATA="$PERFDATA ${MODE}sector_reads=`echo $ONELINE | awk '{ printf "%f",($6-'$READSEC')/'$DIVIDER'; }'`"
READSEC=`echo $ONELINE | awk '{ printf "%f",$6; }'`
PERFDATA="$PERFDATA ${MODE}time_reads=`echo $ONELINE | awk '{ printf "%f",($7-'$READTIM')/'$DIVIDER'; }'`ms"
READTIM=`echo $ONELINE | awk '{ printf "%f",$7; }'`
PERFDATA="$PERFDATA ${MODE}total_writes=`echo $ONELINE | awk '{ printf "%f",($8-'$WRITEOPS')/'$DIVIDER'; }'`"
WRITEOPS=`echo $ONELINE | awk '{ printf "%f",$8; }'`
PERFDATA="$PERFDATA ${MODE}sector_writes=`echo $ONELINE | awk '{ printf "%f",($10-'$WRITESEC')/'$DIVIDER'; }'`"
WRITESEC=`echo $ONELINE | awk '{ printf "%f",$10; }'`
PERFDATA="$PERFDATA ${MODE}time_writes=`echo $ONELINE | awk '{ printf "%f",($11-'$WRITETIM')/'$DIVIDER'; }'`ms"
WRITETIM=`echo $ONELINE | awk '{ printf "%f",$11; }'`
#PERFDATA="$PERFDATA ${MODE}curr_io=`echo $ONELINE | awk '{ printf "%f",($12-'$IOCNT')/'$DIVIDER'; }'`"
IOCNT=`echo $ONELINE | awk '{ printf "%f",$12; }'`
PERFDATA="$PERFDATA ${MODE}time_io=`echo $ONELINE | awk '{ printf "%f",($13-'$IOTIM')/'$DIVIDER'; }'`ms"
IOTIM=`echo $ONELINE | awk '{ printf "%f",$13; }'`

#echo "DEBUG: time_reads $READTIM time_writes $WRITETIM time_io $IOTIM"

echo "OK - Statistics read|$PERFDATA"
exit 0