From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Thu, 30 Aug 2007 12:13:55 -0700 (PDT) Received: from sandeen.net (sandeen.net [209.173.210.139]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id l7UJDp4p015058 for ; Thu, 30 Aug 2007 12:13:53 -0700 Message-ID: <46D716FC.9030905@sandeen.net> Date: Thu, 30 Aug 2007 14:14:04 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: ZFS, XFS, and EXT4 compared References: <1188454611.23311.13.camel@toonses.gghcwest.com> <1188457666.24970.94.camel@edge.yarra.acx> <20070830132002.GA4086@infradead.org> <46D71318.2050604@sandeen.net> <1188500941.8980.20.camel@toonses.gghcwest.com> In-Reply-To: <1188500941.8980.20.camel@toonses.gghcwest.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: "Jeffrey W. Baker" Cc: zfs-discuss@opensolaris.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org Jeffrey W. Baker wrote: > On Thu, 2007-08-30 at 13:57 -0500, Eric Sandeen wrote: >> barrier seems to hurt badly on xfs, too. Note: barrier is off by >> default on ext[34], so if you want apples to apples there, you need to >> change one or the other filesystem's mount options. If your write cache >> is safe (battery backed?) you may as well turn barriers off. I'm not >> sure offhand who will react more poorly to an evaporating write cache >> (with no barriers), ext4 or xfs... > > I didn't compare the safety of the three filesystems, Understood > but I did have > disk caches disabled Oh, so for the SW raid tests the individual disks had no write cache?f > and only battery-backed caches enabled. Do you > need barriers without volatile caches? As far as I understand it, then nope, you don't need it, and you're hurting performance with it. -Eric