From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hubert Verstraete Subject: first partition on partitionable RAID-5 array Date: Wed, 12 Mar 2008 16:21:27 +0100 Message-ID: <47D7F4F7.3040006@free.fr> References: <47AC7463.7000502@free.fr> <20080208081649.rfx07p98ckcgc0sg@estone.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20080208081649.rfx07p98ckcgc0sg@estone.ca> Sender: linux-raid-owner@vger.kernel.org To: michael@estone.ca Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids michael@estone.ca wrote: > My symptons were similar that any partitionable Raid 5 array would be > slower, but ony on the first partition. > mdadm version 2.5.6 > kernel 2.6.18 > > Mike Regarding the slow write performance on the first partition of a partitionable RAID-5 array, actually this is not linked with the first partition. This issue happens when the partition does not start on a cylinder, and this is almost always the case for the first partition which does not start on the first sector of the first cylinder (some space is reserved for the partition table). This symptom doesn't exist on RAID-1. Does anyone know why ? Hubert