Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762681AbZCXT5j (ORCPT ); Tue, 24 Mar 2009 15:57:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758875AbZCXT52 (ORCPT ); Tue, 24 Mar 2009 15:57:28 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:48972 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756528AbZCXT51 (ORCPT ); Tue, 24 Mar 2009 15:57:27 -0400 Message-ID: <49C93AB0.6070300@garzik.org> Date: Tue, 24 Mar 2009 15:55:28 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Linus Torvalds CC: Theodore Tso , Ingo Molnar , Alan Cox , Arjan van de Ven , Andrew Morton , Peter Zijlstra , Nick Piggin , Jens Axboe , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 References: <49C87B87.4020108@krogh.cc> <72dbd3150903232346g5af126d7sb5ad4949a7b5041f@mail.gmail.com> <20090324091545.758d00f5@lxorguk.ukuu.org.uk> <20090324093245.GA22483@elte.hu> <20090324101011.6555a0b9@lxorguk.ukuu.org.uk> <20090324103111.GA26691@elte.hu> <20090324132032.GK5814@mit.edu> <20090324184549.GE32307@mit.edu> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.5 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1406 Lines: 40 Linus Torvalds wrote: > But I really don't understand filesystem people who think that "fsck" is > the important part, regardless of whether the data is valid or not. That's > just stupid and _obviously_ bogus. I think I can understand that point of view, at least: More customers complain about hours-long fsck times than they do about silent data corruption of non-fsync'd files. > The point is, if you write your metadata earlier (say, every 5 sec) and > the real data later (say, every 30 sec), you're actually MORE LIKELY to > see corrupt files than if you try to write them together. > > And if you write your data _first_, you're never going to see corruption > at all. Amen. And, personal filesystem pet peeve: please encourage proper FLUSH CACHE use to give users the data guarantees they deserve. Linux's sync(2) and fsync(2) (and fdatasync, etc.) should poke the block layer to guarantee a media write. Jeff P.S. Overall, I am thrilled that this ext3/ext4 transition and associated slashdotting has spurred debate over filesystem data guarantees. This is the kind of discussion that has needed to happen for years, IMO. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/