Linux command for hda shutdown?

[canis]

Is there a command I can use to shutdown the hard drive in linux? When I power down the computer I see a message hda:shutdown and the hard drive powers down. Is there a way to do this while the computer is powered up? And is there a command to wake the hard drive again?

 

[Nothinman]

You can tweak the power save timeout or just force it into the lowest setting with hdparm. But once your distribution moves to libata I'm not sure how you could accomplish that.