From owner-freebsd-questions@FreeBSD.ORG Thu May 13 16:27:40 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E0AED16A4CE for ; Thu, 13 May 2004 16:27:40 -0700 (PDT) Received: from mxfep02.bredband.com (mxfep02.bredband.com [195.54.107.73]) by mx1.FreeBSD.org (Postfix) with ESMTP id 996A243D41 for ; Thu, 13 May 2004 16:27:39 -0700 (PDT) (envelope-from peter.schuller@infidyne.com) Received: from scode.mine.nu ([83.226.138.17] [83.226.138.17]) by mxfep02.bredband.com with ESMTP id <20040513232737.BZVI14728.mxfep02.bredband.com@scode.mine.nu>; Fri, 14 May 2004 01:27:37 +0200 Received: from localhost (localhost [127.0.0.1]) by scode.mine.nu (Postfix) with ESMTP id 1D0A7157AA7; Fri, 14 May 2004 01:30:09 +0200 (CEST) From: Peter Schuller To: freebsd-questions@freebsd.org Date: Fri, 14 May 2004 01:30:07 +0200 User-Agent: KMail/1.6 References: <40A32D0F.5050101@yahoo.co.uk> <200405132247.33270.peter.schuller@infidyne.com> <86isf0dm1f.fsf@borg.borderworlds.dk> In-Reply-To: <86isf0dm1f.fsf@borg.borderworlds.dk> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200405140130.07120.peter.schuller@infidyne.com> cc: Christian Laursen Subject: Re: The journalling file system saga X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 May 2004 23:27:41 -0000 > [Problems with softupdates] > > > Yet another problem is that an fsync() no longer guarantees that data is > > on disk, even with write caching disabled on the media. This doesn't > > break things like PostgreSQL provided that the order of writes is > > preserved, but it does break things like MTA:s that want to guarantee > > that critical data has been commited to persistent storage before > > signaling success to an external entity (SMTP client). > > fsync(2) works as advertised with softupdates enabled so that shouldn't > cause any problems for applications that are written properly. Ah thanks! I was under the distinct impression that was not the case. This is indeed good news. I can now rest easy running PostgreSQL without disabling soft updates. Perhaps a document would be in order describing/detailing all the details such as this about soft updates, all in one place. What I know I have mostly gathered by reading papers and random mailinglist postings about certain specifics. Is there such a thing in existence? If not I may try to put one together, for other people like me. -- / Peter Schuller, InfiDyne Technologies HB PGP userID: 0xE9758B7D or 'Peter Schuller ' Key retrieval: Send an E-Mail to getpgpkey@scode.org E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org