If you have a PC or a server passing of the time with no activity on the disk, can save a little on the electricity bill if the halt. It's true that can make configuring power management on your desktop environments (KDE, Gnome, etc.) but what I present here is a simple and rapid method for manually configuring this mechanism, ie the operating system Bash.
The tool to use hdparm is used to but to suspend the operation of hard disks can also adjust parameters of cache, DMA, or even acoustic noise, among others.
- Installation: aptitude install hdparm  
- Suspend for 2 minutes: hdparm-S 24 /dev/ sda
- Check the condition of the disk: hdparm -C /dev/sda
- Configure the permanent suspension: vim /etc/hdparm.conf - And add at end of file the following code:  
/dev/sda {
       spindown_time = 24  
}  
- Then you just have to restart your PC, or the service - /etc/init.d/hdparm reload 

Note: the sda is the disk ID in Linux, in your case is hard to see that they have, they can do it as fdisk-l and then with the tool Partition Editor (GParted). If you have only one SATA disk to start is sda if hda is an IDE. If they are not much inside it, then I suggest you to search or ask here on the blog:)