From: Valerie Aurora Subject: Re: ext3 default journal mode Date: Mon, 20 Jul 2009 19:04:03 -0400 Message-ID: <20090720230402.GB26687@shell> References: <4A63DB89.2060306@redhat.com> <20090720212904.GI2416@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ric Wheeler , "linux-ext4@vger.kernel.org" , "Stephen C. Tweedie" , Eric Sandeen , Andreas Dilger , Chris Mason , Josef Bacik , Mingming Cao To: Theodore Tso Return-path: Received: from mx1.redhat.com ([66.187.233.31]:40237 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752418AbZGTXGL (ORCPT ); Mon, 20 Jul 2009 19:06:11 -0400 Content-Disposition: inline In-Reply-To: <20090720212904.GI2416@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Jul 20, 2009 at 05:29:04PM -0400, Theodore Tso wrote: > Here's a revised proposal for the KCONFIG text. > > Hopefully this is balanced about the two sides of the issue, without > explicitly advocating for one choice versus another. > > What do people think? I think it's extremely accurate and detailed, but too long - people's brains turn off after about the 15th line or so. Here's an attempt to distill your description down and refer out to another document (which one?) for people who want to learn more. (Sorry for the whitespace damage.) -VAL config EXT3_DEFAULTS_TO_ORDERED bool "Default to 'data=ordered' in ext3" depends on EXT3_FS help If the mount options for an ext3 filesystem do not include a journal mode, mount it in "data=ordered" mode. The journal mode options for ext3 have different tradeoffs between when data is guaranteed to be on disk and performance. Many applications assume "data=ordered" semantics and may lose, destroy, or reveal other user's data in other journal modes. However, "data=ordered" mode can also result in major performance problems, including long delays before an fsync() call returns. For details, see: XXX some document Use "data=ordered" mode unless you know it is causing a performance problem for your workload. If you are unsure, say 'Y'.