Green hard disk drives

[Ralf Mardorf]

On Thu, 20 Aug 2015 00:40:55 +0100, João M. S. Silva wrote:
>Maybe you could help me clarify something from your experience: in my 
>case, since the disk I'm talking about is the system disk (root 
>partition) it is almost impossible to have it go to sleep, right?

I don't know.

Assumed that even an idle install needs to access some files, couldn't
it be done to files in tmpfs?

Is there some monitoring that wakes up root partitions?

I only want my external data drive to go to sleep.

Btw. I copied the config of an Arch Linux kernel and will build the same
kernel for my Wily install:

[root at archlinux rocketmouse]# t=10800;y=$(smartctl -A /dev/sdc|grep Lo|awk '{print $NF}');sleep $t;x=$(smartctl -A /dev/sdc|grep Lo|awk '{print $NF}');l=$(uname -r)_$(uname -m).$(printf $(cat /etc/issue));echo $l $x-$y=$((x-y)) spins in $(($t/60/60)) hours;zcat /proc/config.gz > /mnt/moonstudio/usr/src/config-$l
3.10.61-rt65-1-rt-lts_x86_64.Arch 15295-15294=1 spins in 3 hours

Only smartctl waked up the drive.

By running the same kernel release, build with the same config, I can rule
out the kernel being the culprit.