From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 29 Mar 2007 08:33:31 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with SMTP id l2TFXL6p030157 for ; Thu, 29 Mar 2007 08:33:23 -0700 Date: Fri, 30 Mar 2007 02:18:58 +1100 From: David Chinner Subject: Re: XFS and write barriers. Message-ID: <20070329151858.GI32597093@melbourne.sgi.com> References: <17923.11463.459927.628762@notabene.brown> <17927.19372.553410.527506@notabene.brown> <20070326090456.GO32597093@melbourne.sgi.com> <200703291656.22084.Martin@lichtvoll.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200703291656.22084.Martin@lichtvoll.de> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Martin Steigerwald Cc: linux-xfs@oss.sgi.com On Thu, Mar 29, 2007 at 04:56:21PM +0200, Martin Steigerwald wrote: > Am Montag 26 März 2007 schrieb David Chinner: > > > > Is there some mount flag to say "cope without barriers" or "require > > > barriers" ?? > > > > XFs has "-o nobarrier" to say don't use barriers, and this is > > *not* the default. If barriers don't work, we drop back to "-o > > nobarrier" after leaving a loud warning inthe log.... > > Hello David! > > Just a thought, maybe it shouldn't do that automatically, but require the > sysadmin to explicitely state "-o nobarrier" in that case. And prevent most existing XFS filesystems from mounting after a kernel upgrade? Think about the problems that might cause with XFs root filesystems on hardware/software that doesn't support barriers.... Default behaviour is tolerant - it tries the safest method known and if it can't use that it tells you and then continues onwards. That's a good default to have. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group