Power savings on USB Hard drives

[Kevin Oberman]

> Date: Sun, 02 Dec 2007 16:15:05 -0800
> From: Nate Lawson <nate at root.org>
> Sender: owner-freebsd-acpi at freebsd.org
> 
> Laurent LEVIER wrote:
> > Hi Guys,
> > 
> > I am using FreeBSD 6.2, soon 7.0 over a server and a laptop.
> > 
> > I would like, on both configurations, to be able to have hard drive
> > power savings as on internal IDE drives.
> > 
> > At the moment, my external USB2 drive, when mounted but even not
> > adresses, keeps running permanently despite it is just mounted for
> > backups (no access out of backup times on sunday then).
> > 
> > I digged on mailing lists, but cant find why the HD keep running.
> > 
> > Can someone help?
> > 
> > Thanks in advance
> > 
> > Brgrds
> 
> This is outside the realm of acpi.  Have you tried the ataidle ported
> application?  It works for most internal drives but I'm not sure how it
> would do over USB.

Almost all external USB drives use umass and are not handled as ATA but
as SCSI. As such, camcontrol is the tool that should probably be
used, but I have no such devices and I don't know what the appropriate
command might be.

Asking on usb@ might provide the needed information.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 224 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-acpi/attachments/20071203/205814f5/attachment.pgp