#!/bin/sh

# dynhdparm is a script to deactivate harddiscs with "hdparm -y" if
# they are not used. I had this running as cron job on a fileserver.
#
# Author: Johannes Findeisen <you@hanez.org>
#
# Usage: dynhdparm /dev/hda
# Or: dynhdparm /dev/hda /dev/hdb
#
# Note: This script will not work to disable devices where the root
# partition resides on.

if [ $# -lt 1 ]; then
  echo "You need at least to set one device as paramater"
  echo "Example: dynhdparm /dev/hdd /dev/sda"
  echo ""
  exit
fi

DEVICES=$@
LSOFDATA=""

for DEVICE in $DEVICES; do
  PARTITIONS=`cat /etc/mtab | grep $DEVICE | cut -d " " -f 2`
  for PARTITION in $PARTITIONS; do
    LSOFDATA=$LSOFDATA`lsof | grep $PARTITION`
  done
  if [ ${#LSOFDATA} -lt 1 ]; then
    HDPARMOUT=`hdparm -y $DEVICE`
  fi
done