From owner-freebsd-questions Sun Feb 10 5:38:52 2002 Delivered-To: freebsd-questions@freebsd.org Received: from smtp2.mbox.com.au (203-134-146-019.cust.pth.iprimus.net.au [203.134.146.19]) by hub.freebsd.org (Postfix) with ESMTP id BFDBB37B419 for ; Sun, 10 Feb 2002 05:38:43 -0800 (PST) Received: from nms2.mbox.com.au (webmail.mbox.com.au [192.168.20.4]) by smtp2.mbox.com.au (Sun Internet Mail Server sims.4.0.2000.05.17.04.13.p6) with ESMTP id <0GRB00C6AKDNXA@smtp2.mbox.com.au> for freebsd-questions@FreeBSD.ORG; Sun, 10 Feb 2002 21:34:40 +0800 (WST) Received: from mbox.com.au ([127.0.0.1]) by nms2.mbox.com.au (Netscape Messaging Server 4.15) with ESMTP id GRBKF601.H05 for ; Sun, 10 Feb 2002 21:35:30 +0800 Date: Mon, 11 Feb 2002 00:35:30 +1100 From: BSD Freak Subject: What I've gathered about the soft updates discussion To: FreeBSD Questions Message-id: <1059024105b581.105b5811059024@mbox.com.au> MIME-version: 1.0 X-Mailer: Netscape Webmail Content-type: text/plain; charset=us-ascii Content-language: en Content-disposition: inline Content-transfer-encoding: 7BIT X-Accept-Language: en Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hiya all, Please excuse me and if I sound ignorant but I am really trying to get my head around soft updates and UNIX (especially FreeBSD) file systems in general. I think the discussion on the topic so far has been very good and for everyone's sake (and mine) here are a few things I've gathered so far: 1. Soft updates is a Good Thing(TM). According to the tuning manpage it gauruntees file system consistency but along with write caching (enabled in FreeBSD 4.4+ by default) can lead to data loss. At least to me this seemed contradictory at first but I think this is what it means (and please correct me if I am mistaken as I have not actually run tests to prove any this this yet): if you have soft updates enabled and your system is shut down uncleanly (ie power failure or crash) an fsck will be run upon reboot but there will be no metadata or data corruption ( the fsck is only to retreive lost space), however you may lose the actual data written within the last minute or so. Please add to this "knowledge base" if you have something you know to be true (not guessing). I would really like to here from someone authoratitive on the matter (ie one of the FreeBSD developers who has worked on the actual soft updates code etc....) Thanks for your patience everyone.... :-) --------------------------------------------------------------------- Would you like to receive faxes to your personal email address? You can with mBox. Visit http://www.mbox.com.au/fax To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message