FreeNAS: switch off automatically when not in use

If you use your NAS at home like I do, you don't need it active all the time. Unfortunately, FreeNAS does not have a built-in feature to shut down the NAS when it is not in use - i.e. no computer in the network is online. At FreeNAS Forum and in the PCGH Extreme Forum there are instructions on how to use a cronjob to test regularly (I check every 15 minutes) whether a computer is still responding to a ping.

More problematic is the automatic start. Unfortunately FreeBSD (which is the basis for FreeNAS) version 8.2 does not support Wake-On-LAN with the onboard network card of my HP N36L. This can be solved with a hand patched FreeNAS (which is rather complicated) or with another network card: my choice was the Intel EXPI9301CT PCI Expresswhich, according to various reports, is to be supported and is available in stores for 25,-Euro. The script, which I have adapted a little, is originally from the FreeNAS forum and can be found behind the "more..." link. After that it just needs to be set up as a cronjob.

#!/bin/bash
HOST1=192.168.0.33 #IP of the first PC
HOST2=192.168.0.35 #IP of the second PC
ip_range=192.168.0. #Network address of the own network without the host part
ip=40 #check network from IP address 40

_exit () {
case $1 in
  1) echo "No Shutdown - At least one of the PCs is switched on" ;;
  2) echo "No PC online - Shutdown" ; shutdown -p now ;;
esac
exit $1;
}

# Check if PC's are on
if [ `ping -c 1 -i 1 $HOST1 | grep -wc 100.0%` -eq 0 ] [ `ping -c 1 -i 1 $HOST2 | grep -wc 100.0%` -eq 0 ] ;
then _exit 1; cancel #, a PC is running
# If no PC is on, go to check if PC's in IP range are on
else

# Check if PC's in IP range are on
  while [ $ip -le 45 ] #check network to host unit 45
do
  ping -c 1 -i 1 $ip_range$ip #ping with the composite IP address from the above variables "ip" and "i
  if [ `ping -c 1 -i 1 $ip_range$ip | grep -wc 100.0%` -eq 0 ] #If one of the hosts responds to the ping, do not shut down
then _exit 1 #exit with exit 1 (no shutdown)
fi
 ip=$(( $ip+1 )) 1TP3Height Host portion always by 1
done

_exit 2 # no PC has responded, shutdown
fi

The script has two parts: the first one (up to line 18) checks if one of the fixed computers is on. The part from line 22 on checks a range of IP addresses, in this example from 192.168.0.40 to 192.168.0.45. What you have to keep in mind in general: also devices like iPhone or iPad return a ping and would prevent the NAS from shutting down. Therefore, in most networks, it will be best to check for only a few specific IP addresses and comment out the check for an IP address range.

Important: the call of the - in my case named shutdowncheck.sh - script must be done with absolute path, otherwise the cronjob can't find it. In my case the following must be entered as cronjob:

sh /mnt/Data/shutdowncheck.sh

As soon as the new network card is delivered, I will write an update accordingly, which will be about FreeNAS and Wake-On-Lan (short WOL) - until then, the NAS will be turned on manually when it is needed.