[Grml] Boot USB sans IDE noise

[Mark]

One user noticed that older IDE drives (CD, HDD) make noise, depending
on age, case vibrations.  His USB drive is very quiet.  He boots grml
from that.

Can he boot from USB without powering IDE drives?  Grml has an orderly
IDE power-off procedure at shutdown.  You hear the IDE hard drives click
off one by one.  The question is best method to invoke the commands at
boot time.

Of course he can always unplug the power cables manually :-)  But
customers don't like that. :-)  Software control is better anyway.