From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: how to use mkfs.ext3 "stride=" on LVM on RAID correctly? Date: Thu, 28 Feb 2008 10:38:09 +0100 Message-ID: <47C68101.4020406@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit To: Linux-Raid , LVM general discussion and development , LKML Return-path: Received: from mail.syneticon.net ([213.239.212.131]:36712 "EHLO mail2.syneticon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754160AbYB1JiQ (ORCPT ); Thu, 28 Feb 2008 04:38:16 -0500 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Lately, I had a serious performance problem on a 1.2 TB ext3 filesystem placed on LVM, which was placed on Linux RAID-5. Luckily, it was possible to alleviate much of this problem by removing internal bitmap from RAID-5 and by using anticipatory IO scheduler. As suggested earlier by Theodore Tso in "very poor ext3 write performance on big filesystems" thread on linux-fsdevel list, I should have used "mke2fs -E stride option to make sure all of the bitmaps don't get concentrated on one hard drive spindle". Although the fine mkfs.ext3 manual gives some basic information on how to do it if you place the whole filesystem on a RAID array, it is not clear to me how it should be done correctly if I want to create a ext3 filesystem on LVM on RAID-5. Any helpful hints? -- Tomasz Chmielewski http://wpkg.org