From owner-freebsd-questions@FreeBSD.ORG Mon Oct 14 20:46:18 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 830D5AB2 for ; Mon, 14 Oct 2013 20:46:18 +0000 (UTC) (envelope-from demelier.david@gmail.com) Received: from mail-we0-x22f.google.com (mail-we0-x22f.google.com [IPv6:2a00:1450:400c:c03::22f]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 1844426A8 for ; Mon, 14 Oct 2013 20:46:17 +0000 (UTC) Received: by mail-we0-f175.google.com with SMTP id t61so7514078wes.20 for ; Mon, 14 Oct 2013 13:46:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=oaPH5Uy3CXru4K96Fpm5IOEMA250AB/76vCpRUqotTM=; b=Q8Hshj1MbQJRykZN0TQTV25p88mHjS5jKNQAacW8vndRutgR6raId53VEoSwZGxJxk txQbDFa76CiS0NN2CvRYGDnEkksdE0mArT3PivNkVqaG6jYt/w7BM3EMUddNmsb5/i7n aix2YGuPUP5wyo4Zu6XuvZaO55hxJdZQdHbb6ozHR5A/pJqyp+9x8e/lhMfOYGViDIJf Cu94hhn5RDVJiHy1ZhiVS0kgzAhVRnkBwRuDIRdjBnlRdE8FG8GbOevwbHXbd44F5Iji pc7wo4GEcLxI7LA/Tsv2iRqNeYStfC+DLdHYlPc0QZ0zdNPKyij0BHDKuatMHLinGfaD 1UZg== X-Received: by 10.180.109.33 with SMTP id hp1mr10001818wib.45.1381783576621; Mon, 14 Oct 2013 13:46:16 -0700 (PDT) Received: from [192.168.0.10] (171.33.91.91.rev.sfr.net. [91.91.33.171]) by mx.google.com with ESMTPSA id d11sm37797415wic.4.2013.10.14.13.46.15 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 14 Oct 2013 13:46:16 -0700 (PDT) Message-ID: <525C580C.9070201@gmail.com> Date: Mon, 14 Oct 2013 22:46:04 +0200 From: David Demelier User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Adam Vande More , CeDeROM Subject: Re: SU+J Lost files after a power failure References: <525A6831.5070402@gmail.com> <20131014133953.58f74659@gumby.homeunix.com> <525C1D1C.9050708@gmail.com> <525C2554.7080203@pchotshots.com> <525C2FBC.4080808@cran.org.uk> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Bruce Cran , Brad Mettee , FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Oct 2013 20:46:18 -0000 On 14.10.2013 20:43, Adam Vande More wrote: > On Mon, Oct 14, 2013 at 1:33 PM, CeDeROM > wrote: > > Thank you for explaining :-) So it looks that it would be sensible to > force filesystem check every n-th mount..? > > > Please explain the logic in which this helps anything. > > > Or to do a filesystem check > after crash..? > > > Already standard behavior as implicitly seen in this thread. > > > Are there any flags like that to mark filesystem > unclean and to force fsck after n-th mount? > > > No and any fs that requires such a system is broken by design. > > > That would assume > disabling journal and soft updates journaling I guess..? > > What would be the best option for best data integrity in case of > crash? > > > mount -o sync or use ZFS. Both require hardware that correctly report > success to fsync. I personnally love ZFS and use it massively on my server, but for a desktop I think this is a real overkill. Also I don't have so much RAM to waste for that. I think UFS is enough, however as a modern operating system I don't expect any data corruption by default using SU+J. The filesystem domain is not a thing I really know deeply, so thanks for all you explanation. PS: the power failure is not the only way that does not shutdown cleanly the system. There are kernel panics, crash and such of course. Those which appears sometimes too. Regards,