Use Less Power on Your NAS

Inspired by my read of this article http://sandeen.net/wordpress/computers/how-to-build-a-10w-6-5-terabyte-commodity-x86-linux-server/ I wanted to do some experimentation on my own NAS server.

The biggest power users (aside from the CPU) are the hard drives. In my NAS I have (5) 3TB WD Red Drives, and (1) 2TB WD Red Drive as well as a pair of Samsung 850 based SSDs. Of course the spinning disks consume the most power. I’m able to determine this based on the UPS which I have connected to the NAS. It has a nice little power meter built-in which I’m sure isn’t extremely accurate but is good enough for my needs.

After much experimentation with the options provided in the article above I found the only things to make a noticeable difference on my NAS were the spindowns of the mechanical harddrives.

Using the following script I was able to cut down my idle power draw from ~72 watts –> ~54 watts for an 18 watt savings or 25% which isn’t too bad!

#!/bin/bash

echo "Setting Power down to 60 seconds."
hdparm -S 12 /dev/sda
hdparm -S 12 /dev/sdb
hdparm -S 12 /dev/sdc
hdparm -S 12 /dev/sde
hdparm -S 12 /dev/sdf

hdparm -S 12 /dev/sdd

echo "Powering Down Hard drives immediately."
hdparm -y /dev/sda
hdparm -y /dev/sdb
hdparm -y /dev/sdc
hdparm -y /dev/sde
hdparm -y /dev/sdf

hdparm -y /dev/sdd