I'm sure you've heard this before...

[Bruce Cran]

On Wed, 28 Oct 2009 20:12:06 -0400
Henry Olyer <henry.olyer at gmail.com> wrote:

> I want to turn the disks off.
> 
> I sometimes run large jobs and want to switch down the drives.
> 
> On some IBM blades, I have FBSD 6.1, on another machine I am using
> 7.2. 

If they're ATA drives you can use my ATAidle utility from
sysutils/ataidle.  In FreeBSD 7 you can also use the "spindown" command
that's been added to atacontrol(8).

-- 
Bruce Cran