From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: ATA support for 4k sector size Date: Wed, 25 Feb 2009 20:07:35 -0700 Message-ID: <20090226030735.GA16891@parisc-linux.org> References: <1235600698-6446-1-git-send-email-matthew@wil.cx> <49A5CBF7.9000501@zytor.com> <20090226025043.GJ1363@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:40822 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752451AbZBZDHx (ORCPT ); Wed, 25 Feb 2009 22:07:53 -0500 Content-Disposition: inline In-Reply-To: <20090226025043.GJ1363@mit.edu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Theodore Tso , "Martin K. Petersen" , "H. Peter Anvin" , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, sandeen@redhat.com On Wed, Feb 25, 2009 at 09:50:43PM -0500, Theodore Tso wrote: > On Wed, Feb 25, 2009 at 06:27:18PM -0500, Martin K. Petersen wrote: > > Because of 63-sector legacy problems a bunch of ATA vendors will > > initially ship 512/4096 drives that are not naturally aligned. > > I.e. logical sector 63 will be aligned on a 4KB hardware sector > > boundary to overcome the misaligned default partitioning. > > Are we *sure* that this is what they plan to be doing? Is there a way > we can query the hardware to find out for sure what drives are doing > what? The drive I have that's pretending to be a 512/4k drive reports this: $ sudo sg_readcap -l /dev/sdc Read Capacity results: Protection: prot_en=0, p_type=0 Last logical block address=625142447 (0x2542eaaf), Number of logical blocks=625142448 Logical block length=512 bytes Logical blocks per physical block=3 (log base 2) [actual=8] Lowest aligned logical block address=0 Hence: Device size: 320072933376 bytes, 305245.3 MiB, 320.07 GB This disagrees with Martin's assertion. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."