From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:48687 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940AbaB1EiL (ORCPT ); Thu, 27 Feb 2014 23:38:11 -0500 Date: Fri, 28 Feb 2014 15:38:07 +1100 From: Dave Chinner To: Josef Bacik Cc: Chris Murphy , Btrfs BTRFS Subject: Re: BUG: >16TB Btrfs volumes are mountable on 32 bit kernels Message-ID: <20140228043807.GC13647@dastard> References: <994B6F86-9AF0-4826-8352-8573EE8003B6@colorremedies.com> <530FA8FA.9020700@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <530FA8FA.9020700@fb.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Feb 27, 2014 at 04:07:06PM -0500, Josef Bacik wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 02/27/2014 04:05 PM, Chris Murphy wrote: > > User reports successfully formatting and using an ~18TB Btrfs > > volume on hardware raid5 using i686 kernel for over a year, and > > then suddenly the file system starts behaving weirdly: > > > > https://urldefense.proofpoint.com/v1/url?u=http://www.mail-archive.com/linux-btrfs%40vger.kernel.org/msg31856.html&k=ZVNjlDMF0FElm4dQtryO4A%3D%3D%0A&r=cKCbChRKsMpTX8ybrSkonQ%3D%3D%0A&m=6eUt5RgBggFh930oFrH19iR4z%2BFVzT%2F0%2F4dYPt3g48U%3D%0A&s=5ac126734d7fa1d3238ab09a2ddc021a8dcc8fff7b022560a4d068be2de37c00 > > > > > > > > I think this is due to the kernel page cache address space being > > 16TB limited on 32-bit kernels, as mentioned by Dave Chinner in > > this thread: > > > > https://urldefense.proofpoint.com/v1/url?u=http://oss.sgi.com/pipermail/xfs/2014-February/034588.html&k=ZVNjlDMF0FElm4dQtryO4A%3D%3D%0A&r=cKCbChRKsMpTX8ybrSkonQ%3D%3D%0A&m=6eUt5RgBggFh930oFrH19iR4z%2BFVzT%2F0%2F4dYPt3g48U%3D%0A&s=3e45f9288e6a77bc1a24dded368802c2ab46b812bf59953f74d4ee1d4141f7d2 > > > > So it sounds like it shouldn't be possible to mount a Btrfs volume > > larger than 16TB on 32-bit kernels. This is consistent with ext4 > > and XFS which refuse to mount large file systems. > > > > > > Well that's not good, I'll fix this up. Thanks, Well, don't go assuming there's a problem just because I made an off-hand comment. i.e my comment was simply "maybe it hasn't been tested", and not an assertion that there is a bug or a problem.... Cheers, Dave. -- Dave Chinner david@fromorbit.com