From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Raid-10 mount at startup always has problem Date: Sun, 28 Oct 2007 20:21:34 -0400 Message-ID: <4725278E.1050306@tmr.com> References: <46D3147D.2040201@amfes.com> <46D49F1A.7030409@tmr.com> <46E4A39C.8040509@amfes.com> <46E4A5F0.9090407@sauce.co.nz> <46E4A7C3.1040902@amfes.com> <471F5542.3020504@amfes.com> <471FA485.6010705@tmr.com> <47202D17.3040000@amfes.com> <1193294406.10336.76.camel@firewall.xsintricity.com> <20071026091513.GB32550@percy.comedia.it> <1193426793.10336.302.camel@firewall.xsintricity.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1193426793.10336.302.camel@firewall.xsintricity.com> Sender: linux-raid-owner@vger.kernel.org To: Doug Ledford Cc: Luca Berra , linux-raid@vger.kernel.org List-Id: linux-raid.ids Doug Ledford wrote: > On Fri, 2007-10-26 at 11:15 +0200, Luca Berra wrote: > >> On Thu, Oct 25, 2007 at 02:40:06AM -0400, Doug Ledford wrote: >> >>> The partition table is the single, (mostly) universally recognized >>> arbiter of what possible data might be on the disk. Having a partition >>> table may not make mdadm recognize the md superblock any better, but it >>> keeps all that other stuff from even trying to access data that it >>> doesn't have a need to access and prevents random luck from turning your >>> day bad. >>> >> on a pc maybe, but that is 20 years old design. >> > > So? Unix is 35+ year old design, I suppose you want to switch to Vista > then? > > >> partition table design is limited because it is still based on C/H/S, >> which do not exist anymore. >> Put a partition table on a big storage, say a DMX, and enjoy a 20% >> performance decrease. >> > > Because you didn't stripe align the partition, your bad. > Align to /what/ stripe? Hardware (CHS is fiction), software (of the RAID you're about to create), or ??? I don't notice my FC6 or FC7 install programs using any special partition location to start, I have only run (tried to run) FC8-test3 for the live CD, so I can't say what it might do. CentOS4 didn't do anything obvious, either, so unless I really misunderstand your position at redhat, that would be your bad. ;-) If you mean start a partition on a pseudo-CHS boundary, fdisk seems to use what it thinks are cylinders for that. Please clarify what alignment provides a performance benefit. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979