From owner-freebsd-mobile Wed Jun 7 7:56:12 2000 Delivered-To: freebsd-mobile@freebsd.org Received: from matrix.42.org (matrix.42.org [194.246.250.200]) by hub.freebsd.org (Postfix) with ESMTP id 6008737BD1A for ; Wed, 7 Jun 2000 07:56:03 -0700 (PDT) (envelope-from sec@42.org) Received: (from sec@localhost) by matrix.42.org (8.8.8/8.8.5) id QAA11199 (sender ); Wed, 7 Jun 2000 16:55:55 +0200 (CEST) Date: Wed, 7 Jun 2000 16:55:54 +0200 From: Stefan `Sec` Zehl To: Ollivier Robert Cc: freebsd-mobile@FreeBSD.ORG Subject: Re: spinning down the drive Message-ID: <20000607165554.A8830@matrix.42.org> Mail-Followup-To: Ollivier Robert , freebsd-mobile@FreeBSD.ORG References: <20000606161140.A8303@dophnic.yi.org> <20000606234343.A68786@keltia.freenix.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0i In-Reply-To: <20000606234343.A68786@keltia.freenix.fr>; from roberto@keltia.freenix.fr on Tue, Jun 06, 2000 at 11:43:43PM +0200 I-love-doing-this: really X-Modeline: vim:set ts=8 sw=4 smarttab tw=72 si noic notitle: Accept-Languages: de, en X-URL: http://sec.42.org/ Sender: owner-freebsd-mobile@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, Jun 06, 2000 at 11:43:43PM +0200, Ollivier Robert wrote: > According to Derek Moeller: > > Is this possible? Are there significant hard drive power gains > > if it's spun down in a laptop? > > Considering that you have a sync(2) every 30s (w/o softupdates) and even more > of them with softupdates, I don't see what you'd gain. > > I'd say it takes more power to restart the drive every N seconds than letting > it spin. > > I may be wrong but I don't see it useful. On 2.2.x Systems you could increase the sync interval. Which I set to 3 hours. I then typed 'sync' whenever the hard drive spun up after a read. That way I got a significant longer uptime from my battery. Unfortunately on 3.0 and greater you can't defer writes that much. I've been working on a patch to defer writes as long as possible, which meant to get confident with kernel-hacking at first :). It's unfortunately still far from finished. While we're at this point. Is there a way to figure out if a given disk is spinning or sleeping? CU, Sec -- In 1968 it took the computing-Power of 2 C-64 to fly a rocket to the moon. Now, 1997 it takes the Power of a Pentium 133 to run Microsoft Windows 95. Something must have gone wrong. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message