From owner-freebsd-arch@FreeBSD.ORG Sat Jan 2 22:28:52 2010 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 576451065694 for ; Sat, 2 Jan 2010 22:28:52 +0000 (UTC) (envelope-from julian@elischer.org) Received: from outI.internet-mail-service.net (outi.internet-mail-service.net [216.240.47.232]) by mx1.freebsd.org (Postfix) with ESMTP id 399328FC1C for ; Sat, 2 Jan 2010 22:28:52 +0000 (UTC) Received: from idiom.com (mx0.idiom.com [216.240.32.160]) by out.internet-mail-service.net (Postfix) with ESMTP id 2225222C3; Sat, 2 Jan 2010 14:28:52 -0800 (PST) X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e X-Client-Authorized: MaGic Cook1e Received: from julian-mac.elischer.org (h-67-100-89-137.snfccasy.static.covad.net [67.100.89.137]) by idiom.com (Postfix) with ESMTP id E2B842D6013; Sat, 2 Jan 2010 14:28:50 -0800 (PST) Message-ID: <4B3FC8A2.1090901@elischer.org> Date: Sat, 02 Jan 2010 14:28:50 -0800 From: Julian Elischer User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: Poul-Henning Kamp References: <67020.1262425354@critter.freebsd.dk> In-Reply-To: <67020.1262425354@critter.freebsd.dk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: =?ISO-8859-1?Q?Ulrich_Sp=F6rlein?= , Miroslav Lachman <000.fbsd@quip.cz>, Thomas Backman , freebsd-current@freebsd.org, freebsd-arch@freebsd.org, Pieter de Goeje , Alexander Motin Subject: Re: File system blocks alignment X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Jan 2010 22:28:52 -0000 Poul-Henning Kamp wrote: > In message <20100102050843.GI3508@acme.spoerlein.net>, Ulrich =?utf-8?B?U3DDtnJ > sZWlu?= writes: > >> Sysinstall, fdisk, gpart >> and bsdlabel should all display some fat warning if partition/label >> alignment is not, say at 256kB (a common stripe size, right?) > > You overlook that MBR/Fdisk requires bootable slices to start at a > "track". That means that the propper slice-alignmen typically > will be 8*63=504 sectors. No it doesn't, (or at least it didn't) but it has become custom to do so. You could always put your slice anywhere (within the stupid geometry constraints) but the ENDING cylinder/head/block numbers were taken to be at the END of a cylinder when there were no other ways of working out the geometry, so that you could "infer" the geometry. packet enabled BIOS's made it all go away. It was all forced on us by IBM. > > Unless you want to explore how many BIOS'es still are stupid about > this... >