From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jordan Russell Subject: Re: MD RAID1 performance very different from non-RAID partition Date: Sat, 15 Sep 2007 13:11:15 -0500 Message-ID: <46EC2043.5010006@quo.to> References: <46EB6D67.1000802@quo.to> <20070915070914.GA21515@teal.hq.k1024.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070915070914.GA21515@teal.hq.k1024.org> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Iustin Pop wrote: > Maybe it's because md doesn't support barriers whereas the disks > supports them? In this case some filesystems, for example XFS, will work > faster on raid1 because they can't force the flush to disk using > barriers. It's an ext3 partition, so I guess that doesn't apply? I tried remounting /dev/sda2 with the "barrier=0" option (which I assume disables barriers, looking at the source), though, just to see if it would make any difference, but it didn't; the database build still took 31 minutes. -- Jordan Russell