[2293] in linux-scsi channel archive
Re: How to turn power off on an idle scsi drive.
daemon@ATHENA.MIT.EDU (Eric Youngdale)
Thu Aug 14 23:16:15 1997
Date: Thu, 14 Aug 1997 23:21:49 -0400 (EDT)
From: Eric Youngdale <eric@andante.jic.com>
To: Gabriel Paubert <paubert@iram.es>
cc: Hein Roehrig <roehrig@mpi-sb.mpg.de>, linux-scsi@vger.rutgers.edu,
rjohanne@piper.hamline.edu
In-Reply-To: <Pine.HPP.3.91.970805030320.8656L-100000@gra-ux1.iram.es>
On Tue, 5 Aug 1997, Gabriel Paubert wrote:
>
>
> > Unless you apply the scsi-idle patch (which is being used with varying
> > success by different people, it works pretty well for me), you should
> > not do this on a drive which gets accessed by Linux.
> >
> > Active termination on the device to be powered down could be a
> > problem, probably some SCSI guru here can comment on that.
>
> I'm not an SCSI guru but from my experience:
>
> AFAIK, this command will only spin down the drive but should not affect
> the SCSI interface (and the termination), which remains powered waiting
> for the on command (otherwise it would be pretty useless). Anyway, it
> should cut down quite significantly on power dissipation (more than 2/3).
Keep in mind that spinning up/down a drive can significantly
shorten the lifetime of a disk drive. You *really* only want to be doing
this if you will not be using the drive for an extended period (say a day
or more). Laptops are a special case - most people feel that the power
consumption issues override disk lifetime concerns.
-Eric
