From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: ATA support for 4k sector size Date: Mon, 16 Mar 2009 09:27:27 -0700 Message-ID: <49BE7DEF.1060005@zytor.com> References: <1235600698-6446-1-git-send-email-matthew@wil.cx> <49A5CBF7.9000501@zytor.com> <20090226025043.GJ1363@mit.edu> <20090226030735.GA16891@parisc-linux.org> <49A6B604.1060702@zytor.com> <49A70379.3050306@zytor.com> <87f94c370903160751t6de5ed2t40163a6590ba633@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:56296 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752061AbZCPQ3B (ORCPT ); Mon, 16 Mar 2009 12:29:01 -0400 In-Reply-To: <87f94c370903160751t6de5ed2t40163a6590ba633@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Greg Freemyer Cc: "Martin K. Petersen" , Matthew Wilcox , Theodore Tso , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, sandeen@redhat.com Greg Freemyer wrote: > If the reported geometry of these drives was changed to have sectors / > track be a multiple of 8, wouldn't that fix most of the issues. > > ie. If the drive were to report 56 sectors per track, then a > traditional partitioning tool would start the first partition as > sector 56 and a Vista like partitioning tool would place the first > partition at sector 2048. Both would have the same 4K sector > alignment. > > If my logic is sound, anyway to get this recommendation upstream to > hardware manufacturers. It seems like an almost trivial change for > them. > > FYI: It sounds to me like partitioning tools should totally drop > efforts to align with cylinders, instead they should start asking what > the unit of atomic read/writes is at the physical layer and if any > offsets are needed to align the partition with the atomic write areas. > > That would fit better for both SSD technology and for this 4K sectors > issue than trying to continue to support cylinders at all. As long as BIOSes played along with it (which some of them may not do -- remember the geometry that matters is the one reported by the BIOS) However, it definitely would be a major step in the right direction, as it would let *most* systems Do The Right Thing instead of weirdly misaligning the partitions and trying to cope with that. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.