#!/bin/bash
# gbtestdisk 0.1   Copyright (C) 2013 Giulio Bottazzi

#firstly created: Sat Feb  9 13:05:02 CET 2013

#specify the format of the bash 'time' function
TIMEFORMAT="%6R"

#specify the default size (in MB) at the command line
count=1

#specify the default number of replica
repnum=5

#read command line options; the position of the last option is saved
#in OPTIND
while getopts "c:r:hv" opt
do
    case $opt in
	c) count=$OPTARG;;
	r) repnum=$OPTARG;;
	v) verbose=yes;;
	h) help=yes;;
	\?) help=yes;;
    esac
done

if [ "$help" = "yes" ]; then

    cat - <<EOF

testdisk ver. .1   Copyright (C) 2013 Giulio Bottazzi

This command test the disk/filesystem speed for synchronous writing
and reading using the 'dd' command. Statistics are reported for disk
write spead, disk read spead and the spead of reading from the disk
cache.

Simply move in a directroy with write permission and run the script to
test the spead of the partition this directory belong to. It is
possible that the script require root permission. So run it with sudo.

Notice tha the rate reported by this script are in general lower than
the one directly reported by dd. Indeed the rate reported by dd
represents the rate without any lag or synch time. The time reported
by this script are a better approximation of the time effectively used
by a program to open a file, write or read the content and close it.

List of options:
    -h print this help
    -c number of MB of the file size
    -r number of executions of the write/read cycle
    -v verbose output: print information about the performed tests

EOF
    exit
fi

if [ "$verbose" = "yes" ]; then
    echo -e "#filesize $count MB, statistics collected over $repnum read/write cycles"
fi
echo -e "#\twrite MB/s\tread MB/s\tcache MB/s"
for replica in `seq 1 $repnum`; do
    #write to disk
    totaltime=$( time (dd if=/dev/zero of=./tempfile bs=1M count=$count conv=fdatasync,notrunc 2>/dev/null) 2>&1)
    echo -n $(echo "scale=3 ; $count/$totaltime" | bc) " "
    #read from disk
    sudo /sbin/sysctl  vm.drop_caches=3 > /dev/null
    totaltime=$( time (dd if=./tempfile of=/dev/zero bs=1M count=$count 2>/dev/null) 2>&1)
    echo -n $(echo "scale=3 ; $count/$totaltime" | bc) " "
    #read from cache
    totaltime=$( time (dd if=./tempfile of=/dev/zero bs=1M count=$count 2>/dev/null) 2>&1)
    echo -n $(echo "scale=3 ; $count/$totaltime" | bc) " "
    echo " "
    rm ./tempfile
done | gawk 'NR==1 { for(col=1;col<=NF;col++) min[col]=max[col]=sum[col]=$col  }; NR>1 {for(col=1;col<=NF;col++){if($col>max[col]) max[col]=$col; if($col<min[col]) min[col]=$col; sum[col]=sum[col]+$col}}; END {printf "max\t"; for(col=1;col<=NF;col++) printf "%f\t",max[col]; printf "\n"; printf "min\t"; for(col=1;col<=NF;col++) printf "%f\t",min[col]; printf "\n"; printf "avg\t"; for(col=1;col<=NF;col++) printf "%f\t",sum[col]/NR; printf "\n";}'