# !/bin/sh

TMPF1=”/tmp/.hddspindwn-$1-1″
TMPF2=”/tmp/.hddspindwn-$1-2″
FLAG=”/tmp/.hddspindwnflg-$1″
LOG_FILE=/var/log/hddspindown.log
STAMP=`date +”%d.%m.%g %H:%M:%S”`

[ ".$1" != "." ] && disks=$(ls /dev/sd* | grep $1)
if [ ".$disks" = "." ]; then
echo “Please enter a valid disk device” 1>&2
exit 1;
fi

if [ "$(id -u)" != "0" ]; then
echo “This script must be run as root” 1>&2
exit 1
fi

# Get new state from diskstats
nstats=$(cat /proc/diskstats | grep $1)
echo $nstats > $TMPF1

# compare md5 sums
nmd5=”???”
omd5=”???”
[ -f $TMPF1 ] && nmd5=$(md5sum $TMPF1 | sed ‘s/ .*//’)
[ -f $TMPF2 ] && omd5=$(md5sum $TMPF2 | sed ‘s/ .*//’)
echo “$STAMP : Current MD5 : $nmd5″ >> $LOG_FILE
echo “$STAMP : Old MD5 : $omd5″ >> $LOG_FILE

# if no changes, power down
if [ "$nmd5" = "$omd5" ]; then
if [ ! -f $FLAG ]; then
touch $FLAG
hdparm -Y /dev/$1 &>/dev/null
echo “$STAMP : Spindown of /dev/$1 intiated…” >> $LOG_FILE
else
echo “$STAMP : /dev/$1 was already set to standby.” >> $LOG_FILE
fi
else
if [ -f $FLAG ]; then
rm $FLAG
echo “$STAMP : $FLAG removed because of disk-io.” >> $LOG_FILE
fi
fi

# Write current state to file
echo $nstats > $TMPF2