From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: ATA 4 KiB sector issues. Date: Tue, 16 Mar 2010 23:48:32 -0700 Message-ID: <4BA07B40.9090400@zytor.com> References: <4B947393.2050002@kernel.org> <201003100046.24695.arnd@arndb.de> <1158166a1003100114j6ea329fbh84bfad65dcac90bf@mail.gmail.com> <4B9EED55.10201@kernel.org> <1268720060.21384.10.camel@mulgrave.site> <4B9F2388.2030803@kernel.org> <1268745897.21384.14.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:41516 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751981Ab0CQGtM (ORCPT ); Wed, 17 Mar 2010 02:49:12 -0400 In-Reply-To: <1268745897.21384.14.camel@mulgrave.site> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: James Bottomley Cc: Tejun Heo , Denys Vlasenko , Arnd Bergmann , "linux-ide@vger.kernel.org" , lkml , Daniel Taylor , Jeff Garzik , Mark Lord , tytso@mit.edu, hirofumi@mail.parknet.co.jp, Andrew Morton , Alan Cox , irtiger@gmail.com, Matthew Wilcox , aschnell@suse.de, knikanth@suse.de, jdelvare@suse.de On 03/16/2010 06:24 AM, James Bottomley wrote: > > Because the msdos label can only partition in units of cylinders. If > you're using an msdos label, picking the right H/S gets you alignment. > This is doubly false. An MS-DOS partition table can partition at any boundary. Some OSes (like some versions of MS-DOS) needed track alignment because their boot loaders did not support crossing track boundaries. Second, the primary field in the (modern) MS-DOS partition table is an LBA field. The CHS fields are largely historic and useless because of the 1024-cylinder limitation, and by only being 24 bits total. -hpa