From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: ATA 4 KiB sector issues. Date: Tue, 16 Mar 2010 15:22:00 +0900 Message-ID: <4B9F2388.2030803@kernel.org> References: <4B947393.2050002@kernel.org> <201003100046.24695.arnd@arndb.de> <1158166a1003100114j6ea329fbh84bfad65dcac90bf@mail.gmail.com> <4B9EED55.10201@kernel.org> <1268720060.21384.10.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:39881 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965305Ab0CPGWa (ORCPT ); Tue, 16 Mar 2010 02:22:30 -0400 In-Reply-To: <1268720060.21384.10.camel@mulgrave.site> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: James Bottomley Cc: Denys Vlasenko , Arnd Bergmann , "linux-ide@vger.kernel.org" , lkml , Daniel Taylor , Jeff Garzik , Mark Lord , tytso@mit.edu, "H. Peter Anvin" , hirofumi@mail.parknet.co.jp, Andrew Morton , Alan Cox , irtiger@gmail.com, Matthew Wilcox , aschnell@suse.de, knikanth@suse.de, jdelvare@suse.de Hello, James. On 03/16/2010 03:14 PM, James Bottomley wrote: > So, it is true to say that picking a certain H/S geometry (which is > entirely withing the gift of the partitioner) will align msdos label > partitions, but will be don't care for all other labels: all other > partition labels (like gpt) use block as offset and don't have any truck > with the fictitious C/H/S stuff. For any modern Linux and Windows, CHS simply doesn't matter. They don't look at it at all. > The big problem is that 99% of the x86 systems out there still use the > ancient msdos label for their boot disks, so aligning H/S going forwards > will give us a nice "just works" for x86 boxes. What I don't get is that how picking up a custom geometry can make things work when there is *no* reliable way to determine which geometry was used during partitioning once the partitioning is complete. Most BIOSs these days will simply report the geometry as being 255/63 regardless of the geometry used during partitioning. So, how can using a custom geometry give that nice "just works" for x86 boxes when nobody knows what geometry is in use? Thanks. -- tejun