From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: ATA 4 KiB sector issues. Date: Wed, 10 Mar 2010 03:22:59 -0800 Message-ID: <4B978113.80107@zytor.com> References: <4B947393.2050002@kernel.org> <1268031640.4389.11.camel@mulgrave.site> <4B94ACE8.4060400@zytor.com> <87f94c371003091446h62e50257qf884b278c69cfbfa@mail.gmail.com> <4B96E884.6050305@zytor.com> <20100310104615.GA23051@sig21.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:46823 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753015Ab0CJLXu (ORCPT ); Wed, 10 Mar 2010 06:23:50 -0500 In-Reply-To: <20100310104615.GA23051@sig21.net> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Johannes Stezenbach Cc: Greg Freemyer , James Bottomley , Tejun Heo , "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, mkp@mkp.net On 03/10/2010 02:46 AM, Johannes Stezenbach wrote: > On Tue, Mar 09, 2010 at 04:32:04PM -0800, H. Peter Anvin wrote: >> >> It can. The BIOS doesn't care about the partition table at all -- >> all it does is load the MBR. > > A little story for your entertainment pleasure: > > I have a Gigabyte GA-MA78GM-S2H board, and during install > turned off the power after partitioning but before formatting > any partition because I got distracted by something else. > > Result: System could not boot anymore, BIOS hung before > I could get to the "select boot device" screen. This also > happened when I removed the hdd from the boot device > list in BIOS. The last BIOS message was "Verifying DMI Pool Data" > and you can find numerous similar reports by searching for > 'gigabyte bios hang "Verifying DMI Pool Data"'. > > In my case it worked to switch the SATA mode from AHCI to > something else, then wipe the partition table and switch > back to AHCI. But I read on the net that some people had > to format the drive in another PC, or hotplug it after the BIOS > got past "Verifying DMI Pool Data". > Well, yes, there are buggy BIOSes of a gazillion varieties. A fair number of them read the partition table to try to guess what C/H/S geometry the user intended. However, the GPT spec specifically uses a "Protective MBR" to guard against this and other issues like it; it makes the entire disk look to MBR-reading software like a single fully partitioned disk with one large partition on it. -hpa