From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751501AbVH2UK7 (ORCPT ); Mon, 29 Aug 2005 16:10:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751508AbVH2UK6 (ORCPT ); Mon, 29 Aug 2005 16:10:58 -0400 Received: from [212.76.84.38] ([212.76.84.38]:19975 "EHLO raad.intranet") by vger.kernel.org with ESMTP id S1751497AbVH2UK5 (ORCPT ); Mon, 29 Aug 2005 16:10:57 -0400 From: Al Boldi To: Holger Kiehl Subject: Re: Where is the performance bottleneck? Date: Mon, 29 Aug 2005 23:10:39 +0300 User-Agent: KMail/1.5 Cc: linux-kernel , linux-raid References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200508292310.39903.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Holger Kiehl wrote: > Why do I only get 247 MB/s for writting and 227 MB/s for reading (from the > bonnie++ results) for a Raid0 over 8 disks? I was expecting to get nearly > three times those numbers if you take the numbers from the individual > disks. > > What limit am I hitting here? You may be hitting a 2.6 kernel bug, which has something to do with readahead, ask Jens Axboe about it! (see "[git patches] IDE update" thread) Sadly, 2.6.13 did not fix it either. Did you try 2.4.31? -- Al