From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 1 Oct 2001 17:17:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 1 Oct 2001 17:17:42 -0400 Received: from thebsh.namesys.com ([212.16.0.238]:37380 "HELO thebsh.namesys.com") by vger.kernel.org with SMTP id ; Mon, 1 Oct 2001 17:17:31 -0400 Message-ID: <3BB8DD83.96B9220F@namesys.com> Date: Tue, 02 Oct 2001 01:17:55 +0400 From: Hans Reiser Organization: Namesys X-Mailer: Mozilla 4.78 [en] (X11; U; Linux 2.4.4 i686) X-Accept-Language: en, ru MIME-Version: 1.0 To: Neil Brown CC: Mike Fedyk , linux-kernel@vger.kernel.org Subject: Re: Define conflict between ext3 and raid patches against 2.2.19 In-Reply-To: <20010916155835.C24067@mikef-linux.matchmail.com> <15271.11056.810538.66237@notabene.cse.unsw.edu.au> <20010919133811.B22773@mikef-linux.matchmail.com> <15273.7576.395258.345452@notabene.cse.unsw.edu.au> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org More precisely, as long as you understand that resync requires doing the resync offline, and accept that, and remember it, and your colleagues at work remember it:-), you can use it. Personally, I would just go to 2.4 myself. Hans Neil Brown wrote: > > On Wednesday September 19, mfedyk@matchmail.com wrote: > > On Tue, Sep 18, 2001 at 09:08:32PM +1000, Neil Brown wrote: > > > > > > You should be aware that ext3 (and other journalling filesystems) do > > > not work reliably over RAID1 or RAID5 in 2.2. Inparticular, you can > > > get problems when the array is rebuilding/resyncing. > > > > > > But if you only plan to use ext3 with raid0 or linear, you should be > > > fine. > > > > > > > Can you point me to an archive that describes how to trigger this bug? > > > > Was it in linux-raid or ext3-users or ...? > > > > Mike > > I don't remember exactly where or when I read it - either linux-raid > or linux-kernel. It was asserted by Stephen Tweedie. > > The problem is that ext3 is very careful about when it writes buffer > to disk : it won't release a buffer until the relevant journal entry > is committed. > > However when a RAID rebuild happens, every block on the array is read > into the buffer cache (if it isn't already there) and then written > back out again. This defeats the control that ext3 tries to maintain > on the buffer cache. > > I don't know exactly what large-scale effects this might have. It > could be simply that a crash at the wrong time could leave the > filesystem corrupted. But I heard of one person who claimed to get > filesystem corruption after using reiserfs over RAID1 in 2.2, so maybe > it's worse than that. > > If you really need to know, I suggest you ask on ext3-users. > > NeilBrown > - > 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/