From: Cryptooctoploid Subject: Re: data corruption with ext4 (from 2.6.27.4) exposed by rtorrent Date: Wed, 5 Nov 2008 21:13:30 +0100 Message-ID: <319012f0811051213g1f2ed31blf2b4bede3dd9535@mail.gmail.com> References: <3d3ce57e0811030442o377cf2bet212eefba79d714bb@mail.gmail.com> <20081103134008.GE29102@mit.edu> <319012f0811050534i27b7dce1t8120b3a343844adc@mail.gmail.com> <20081105172553.GA29880@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Roc Valles" , linux-ext4@vger.kernel.org To: "Theodore Tso" Return-path: Received: from wf-out-1314.google.com ([209.85.200.170]:23367 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbYKEUNa (ORCPT ); Wed, 5 Nov 2008 15:13:30 -0500 Received: by wf-out-1314.google.com with SMTP id 27so187412wfd.4 for ; Wed, 05 Nov 2008 12:13:30 -0800 (PST) In-Reply-To: <20081105172553.GA29880@mit.edu> Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Nov 5, 2008 at 6:25 PM, Theodore Tso wrote: > Cryptooctoploid, > > Based on some reflection and further discussion on #ext4, I have a > theory which we need to try to prove/disprove that it may be related > to memory pressure combined with the delayed allocation code. > > If you've already dismantled your ext4 setup, maybe you can't test > this, but it would be interesting to know mounting with the -o > nodelalloc makes the problem go away. Yes, -o nodelalloc resolves the issue here. >Also, how much memory do you > have in your system and is your system often under memory pressure? > (i.e., your system often uses swap, and where the amount of free > memory is often near the low water mark where it is trying to evict > memory either by dropping clean pages or writing dirty pages back to > the filesystem and/or swap). I have 2GB of memory and my machine is not under any kind of memory pressure normally.