From owner-freebsd-questions@FreeBSD.ORG Sat Apr 19 21:33:59 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6B04C1065679 for ; Sat, 19 Apr 2008 21:33:59 +0000 (UTC) (envelope-from tl32@next.online.no) Received: from mail42.e.nsc.no (mail42.e.nsc.no [193.213.115.42]) by mx1.freebsd.org (Postfix) with ESMTP id ECF528FC0A for ; Sat, 19 Apr 2008 21:33:58 +0000 (UTC) (envelope-from tl32@next.online.no) Received: from [84.202.253.145] (084202253145.customer.alfanett.no [84.202.253.145]) (authenticated bits=0) by mail42.nsc.no (8.13.8/8.13.5) with ESMTP id m3JLXu1o014241 for ; Sat, 19 Apr 2008 23:33:56 +0200 (MEST) Message-ID: <480A6538.5000102@next.online.no> Date: Sat, 19 Apr 2008 23:33:44 +0200 From: Tore Lund User-Agent: Thunderbird 2.0.0.12 (X11/20080229) MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <790871.1688.qm@web57004.mail.re3.yahoo.com> <9bbcef730804180840y77adff73x7ad0cf90c82633a9@mail.gmail.com> <200804192005.06962.fbsd.questions@rachie.is-a-geek.net> <9bbcef730804191302t31eaf472s1b7e64fe5915b9b1@mail.gmail.com> In-Reply-To: <9bbcef730804191302t31eaf472s1b7e64fe5915b9b1@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: Sidetracked: why gjournal over soft-updates (Was: Re: UFS2 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Apr 2008 21:33:59 -0000 Ivan Voras wrote: > 1) Soft-updates were created in a different time, with different > requirements than modern hard drives (especially desktop hard drives) > can deliver. Especially, SU requires that data it once sends to the > drive gets written immediately, not cached by the drive. Modern > desktop drives don't do that so journaling is today actually safer > than SU The caching can be stopped by putting "hw.ata.wc=0" into /boot/loader.conf. Doesn't that settle this point about safety? > For details, you can search the mailing list archives - what I've said > is nothing original and the topic has been talked about a lot. Since we use softupdates and others use gjournal, one suspects that there are reasons why "real" journaling systems have not been adopted. Once the subject has been raised, it would be nice to get an up-to-date view from someone in the know - as opposed to having to leaf through hundreds of old threads on the topic. TIA. -- Tore