From owner-freebsd-hackers@FreeBSD.ORG Wed Oct 27 13:05:06 2010 Return-Path: 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 5F8641065679; Wed, 27 Oct 2010 13:05:06 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [IPv6:2a01:170:102f::2]) by mx1.freebsd.org (Postfix) with ESMTP id 0D17B8FC16; Wed, 27 Oct 2010 13:05:04 +0000 (UTC) Received: from lurza.secnetix.de (localhost [127.0.0.1]) by lurza.secnetix.de (8.14.3/8.14.3) with ESMTP id o9RD4ela043181; Wed, 27 Oct 2010 15:04:55 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.14.3/8.14.3/Submit) id o9RD4e9Q043179; Wed, 27 Oct 2010 15:04:40 +0200 (CEST) (envelope-from olli) From: Oliver Fromme Message-Id: <201010271304.o9RD4e9Q043179@lurza.secnetix.de> To: arundel@FreeBSD.ORG (Alexander Best) Date: Wed, 27 Oct 2010 15:04:39 +0200 (CEST) In-Reply-To: <20101027124113.GA6206@freebsd.org> X-Mailer: ELM [version 2.5 PL8] MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.3.5 (lurza.secnetix.de [127.0.0.1]); Wed, 27 Oct 2010 15:04:55 +0200 (CEST) Cc: Bruce Cran , Dag-Erling =?iso-8859-15?Q?Sm=F8rgrav?= , mav@FreeBSD.ORG, Tijl Coosemans , freebsd-hackers@FreeBSD.ORG 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Oct 2010 13:05:06 -0000 Alexander Best wrote: > i just stumbled upon PR 144770, where a somebody seems to have mistaken the > spindown value for minutes instead of seconds. so i really think we should have > this warning in atacontrol! > > +1 from brucec, if i understood him correctly. > > another possibility would be of course changing the spindown value from seconds > to minutes. imo this seems very reasonable, because measuring spindown time in > seconds is too fine grained and not intuitive. just like specifying the > 'shutdown -p XX' delay in microseconds would not be useful. ;) No, please don't. Changing the meaning of the value from seconds to minutes will break people's existing setups. I'm also against printing a warning for values less than 600. If I want to set the value to 300, I don't want to be slapped with a useless warning. Also note that 300 (and even much less) might be perfectly reasonable, depending on the kind of device! As a rule of thumb, the smaller a drive, the better it is optimized for many spin up/down cycles. For example, I've got a portable HDD mp3 player that contains a 1.8" disk. When playing an mp3 file, it spins up every 20 seconds or so, reads 500 KB, then spins down again. In my opinion, this is purely a documentation issue. If it is well-documented that the spindown value is given in seconds, then that should be sufficient. Supporting values like "5m" or "1h" would be fine, as long as a value without a letter still means seconds. Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "Python is an experiment in how much freedom programmers need. Too much freedom and nobody can read another's code; too little and expressiveness is endangered." -- Guido van Rossum