User Feedback :: standby in dsl with hdparm

i have open the terminal as root,and i write
hdparm -Y /dev/hda
my hard disk is now sleep,but after 2 minutes resume up automatically...
how to make sleep the pc?
when i go out i like turn the pc on,but the hard disk is always on...
with microsoft windows this operations is very simple...
dsl permit this?

original here.