Uses sar to find top io (ab)users.

gt-topiosar

#!/bin/bash
#% Title: gt-topiosar
#% Author: Eric Windisch
#% License: MIT

# default value...
count=20
#expr="p;"
filter='.'

set -- `getopt c:d:e: $@` >/dev/null 2>&1
while [ $# -gt 0 ]
do
	case "$1" in
		-c) count=$2; shift ;;
		-d) device=$2; shift ;;
		-e) filter=$2; shift ;;
		--) shift; break;;
		-*)
			echo >&2 \
			"usage: $0 [-c count] [-e expr] [-d device] [device...]"
			exit 1;;
		*) break;;
	esac
	shift
done
# push device back into $@
# so we can easily just pass this along
# and keep it in the same array as other devs.
set -- $@ $device

#filter="sed -ne '$expr'"

function topn {
count=$1; shift;
echo "tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util	device"
for line in $(sar -d | sed -n '/Average/ { s/Average:\s\+//; p; }' | sed '1,3d; s/^\(\w\+\|dev\w\+-\w\+\)\s\+\(.*\)/\2\t\1/' | sort -nr | head -n$count | sed 's/\s\+/,/g'); do
	dmaj=$(echo $line | cut -d, -f9 | cut -d- -f1 | sed 's/^dev//;' );
	dmin=$(echo $line | cut -d, -f9 | cut -d- -f2);
	dev=$(sed -n "s/^\s\+//; s/\s\+/,/g; /^${dmaj},${dmin}/p" /proc/partitions | cut -d, -f4)

	if ( echo $dev | grep '^dm' >/dev/null 2>&1 ); then
		dev=$(dmsetup info -c --noheadings -j $dmaj -m $dmin | cut -d: -f1);
	fi

	if [ -n $dev ]; then
		echo $line |
			sed "s/dev${dmaj}-${dmin}/${dev}/; s/,/\t\t/g;";
	fi
done
}

if [ $# -gt 0 ] && [ $count -ge $# ]; then
	echo "IO statistics:"
else 
	echo "Top $count IO users:"
fi

topn $count $filter $@ | column -t