ATA 4 KiB sector issues.
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From: H. Peter Anvin on 10 Mar 2010 00:20 On 03/09/2010 04:14 PM, Daniel Taylor wrote: > > The MBR in a GPT installation doesn't map the first GPT partition, it maps > the entire drive > drive after the first sector, as well as marking it type 0xEE. The start > LBA of the file system > is not correctly located in the MBR. > > I will run some experiments to see if any of the systems on my desk can boot > Linux from a GPT. There is something called a "hybrid MBR", which is basically a GPT disk with a single partition (the current bootable partition) mapped as an MBR partition, instead of marking the whole disk 0xEE. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Mark Lord on 10 Mar 2010 01:10 On 03/09/10 19:00, Tejun Heo wrote: > On 03/09/2010 10:55 PM, Mark Lord wrote: >> On 03/07/10 22:48, Tejun Heo wrote: >> .. >>> Please note that hdparm is misreporting the alignment offset. It >>> should be reporting 512 instead of 256 for offset-by-one drives. >> .. >> >> That issue was fixed quite a while ago. >> Upgrade your elderly copy of hdparm. > > Heh heh, *you* were keeping it from me! Anyways, is there hdparm > devel tree published somewhere? I wandared the SF page for quite a > bit (which for some reason is very difficult to find things in) but I > couldn't find one. If it's not, it might be a good idea to put it on > SF or git.kernel.org? ... No tree. There's just my working copy (private), and the published versions at SF. But yes, SF has gotten incredibly more cryptic to use of late, and I might have to move it somewhere more accessible soon. Cheers! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Gabor Gombas on 10 Mar 2010 02:10 On Tue, Mar 09, 2010 at 04:14:30PM -0800, Daniel Taylor wrote: > I will run some experiments to see if any of the systems on my desk can boot > Linux from a GPT. My desktop with a BIOS from 2005 has no problems with GPT. AFAIK a recent Debian installer automatically chooses GPT if the disk is 2 TB or larger. Gabor -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Matthew Wilcox on 10 Mar 2010 03:00 On Mon, Mar 08, 2010 at 10:41:57AM -0500, Martin K. Petersen wrote: > What I meant to say was that I know ATA supports 4 KB LBS and that > nobody appears to care about it. I sent patches to add support ... they were ignored. Part of the problem is that ATA is heinously broken wrt non-512 byte sector sizes. You have to know which commands work in multiples of the block size, and which commands work in multiples of 512-bytes. There's no easy way to figure it out; you need a table. -- 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." -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Denys Vlasenko on 10 Mar 2010 04:20
On Wed, Mar 10, 2010 at 12:46 AM, Arnd Bergmann <arnd(a)arndb.de> wrote: > On Monday 08 March 2010 04:48:35 Tejun Heo wrote: >> Unfortunately, while Windows can assume that newer releases won't >> share the hard drive with older releases including Windows XP, Linux >> distros can't do that. �There will be many installations where a >> modern Linux distros share a hard drive with older releases of >> Windows. �At this point, I can't see a silver bullet solution. >> >> Partitioners maybe should only align partitions which will be used by >> Linux and default to the traditional layout for others while allowing >> explicit override. �I think Windows XP wouldn't have problem with >> differently aligned partitions as long as it doesn't actually use them >> but haven't tested it. > > Any idea if XP can cope with partition tables that use a 32-sector, 128-head > geometry rather than the default 63-sector, 255-head one? That seems to > be what some flash memory cards are using and it would make any cylinder > aligned partition also 4096-byte aligned, at the cost of moving the > 1024-cylinder boundary from 7.88 GiB to 2 GiB. > > Do we know of anything that requires 63s/255h? 63s/255h is more or less "standard" now. Alignment issues can be solved by picking a good multiple of _heads_ or _cylinders_: For first partition, pick the start at 8th head: cyl 0 head 1 sector 1: LBA sector 63) - bad cyl 0 head 8 sector 1: LBA sector 8*63) - good (4k aligned) For any other partition, pick start cylinder which is a multiple of 8: cyl 8*x head 0 sector 1: LBA sector 8*x*255*63 - good (4k aligned) This will actually work well for *any* geometry, not only for 63s/255h. -- vda -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |