Voy a probar esto que me he encontrado cuando termine de formatear mi HDD USB ->
http://wiki.openwrt.org/doc/howto/storageAutomatic spin down an attached hard disk
If you have attached an external hard disk (e.g. through the USB port) and you don't use the disk all the time, you may want to spin down the disk after some time. One possible reason for this is to reduce the noise. A second reason is that some fanless external racks can get very hot and this is not healthy for the disk.
Unfortunately there is no solution that works always for everybody. The first option to try is provided by the package ''hd-idle'', which will spin down any disk accessible via the SCSI layer. Install it and test if it can spindown the hard disk (let us assume that your disk is /dev/sda):
opkg install hd-idle
hd-idle -t sda
If you can hear the disk spins down, then you can configure the package, the configuration is in /etc/config/hd-idle.
If hd-idle doesn't work, then the next option to try is hdparm:
opkg install hdparm
hdparm -y /dev/sda
If you hear the disk spins down, then create a script /etc/spindown with the following contents:
#!/bin/sh
oldstate=''
n="$2"
while :; do
sleep 60
newstate=$(grep "$1" /proc/diskstats)
if [ "$newstate" = "$oldstate" ]; then
n=$(($n - 1))
[ "$n" != 0 ] || hdparm -y /dev/"$1"
else
n="$2"
oldstate=$newstate
fi
done &
Then add to /etc/rc.local the following command (assuming your disk is /dev/sda and you want to spin it down after 20 minutes of inactivity):
/etc/spindown sda 20
A much easier way is this: if the above command hdparm -y /dev/sda works, insert the following command to /etc/rc.local:
hdparm -S 240 /dev/hda
The setting 240 equals 20 mins, the time coding can be checked on the ''hdparm man page''.
The third option to try is the package sdparm:
opkg install sdparm
sdparm -f -C stop /dev/sda
If you hear the disk spins down, use the script /etc/spindown as in the case of hdparm, however replace the line
[ "$n" != 0 ] || hdparm -y /dev/"$1"
with the line
[ "$n" != 0 ] || sdparm -f -C stop /dev/"$1"
