From owner-freebsd-hackers@FreeBSD.ORG  Thu Sep 16 14:57:22 2010
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@FreeBSD.ORG
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id AF75A1065679;
	Thu, 16 Sep 2010 14:57:22 +0000 (UTC)
	(envelope-from wblock@wonkity.com)
Received: from wonkity.com (wonkity.com [67.158.26.137])
	by mx1.freebsd.org (Postfix) with ESMTP id 4E7EB8FC21;
	Thu, 16 Sep 2010 14:57:22 +0000 (UTC)
Received: from wonkity.com (localhost [127.0.0.1])
	by wonkity.com (8.14.4/8.14.4) with ESMTP id o8GEg04S068467;
	Thu, 16 Sep 2010 08:42:00 -0600 (MDT)
	(envelope-from wblock@wonkity.com)
Received: from localhost (wblock@localhost)
	by wonkity.com (8.14.4/8.14.4/Submit) with ESMTP id o8GEg0Fi068464;
	Thu, 16 Sep 2010 08:42:00 -0600 (MDT)
	(envelope-from wblock@wonkity.com)
Date: Thu, 16 Sep 2010 08:42:00 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: Alexander Best <arundel@FreeBSD.ORG>
In-Reply-To: <20100916004902.GA46401@freebsd.org>
Message-ID: <alpine.BSF.2.00.1009160831560.68314@wonkity.com>
References: <alpine.BSF.2.00.1003051636030.2481@wonkity.com>
	<201009152143.o8FLhE9p022233@lurza.secnetix.de>
	<20100916004902.GA46401@freebsd.org>
User-Agent: Alpine 2.00 (BSF 1167 2008-08-23)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6
	(wonkity.com [127.0.0.1]); Thu, 16 Sep 2010 08:42:00 -0600 (MDT)
Cc: freebsd-hackers@FreeBSD.ORG, mav@FreeBSD.ORG,
	Oliver Fromme <olli@lurza.secnetix.de>
Subject: Re: Summary: Re: Spin down HDD after disk sync or before power off
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 16 Sep 2010 14:57:22 -0000

On Thu, 16 Sep 2010, Alexander Best wrote:

> On Wed Sep 15 10, Oliver Fromme wrote:
>> Warren Block <wblock@wonkity.com> wrote:
>> > [...]
>> > 8. Alexander Motin has an updated CAM version of the ATA system which
>> > will eventually replace the existing one.  In -CURRENT, anyway.  He was
>> > kind enough to look at my event handler.  My understanding is that he is
>> > looking at implementing the head parking/standby mechanism in that new
>> > code.
>>
>> The patch below will work with the new CAM ATA driver
>> (i.e. ada(4) disks).  It adds a sysctl, so you can switch
>> the spin-down off if you're going to just reboot:
>> # sysctl kern.cam.ada.spindown_shutdown=0
>
> i haven't tested your patch yet, but i don't think deciding whether to spin
> down the hdd should be decided merely from the sysctl value.
>
> the hdd should spindown when a shutdown has been issued and not spindown,
> if a reboot has been issued.

It's been a while, but the problem I found when comparing the NetBSD 
code was that there didn't appear to be a way to tell from within the 
FreeBSD driver whether it was a shutdown or reboot.