|From:||"Martin K. Petersen" <martin.petersen-AT-oracle.com>|
|To:||Tejun Heo <tj-AT-kernel.org>|
|Subject:||Re: ATA 4 KiB sector issues.|
|Date:||Mon, 08 Mar 2010 10:18:27 -0500|
|Cc:||"linux-ide-AT-vger.kernel.org" <linux-ide-AT-vger.kernel.org>, lkml <linux-kernel-AT-vger.kernel.org>, Daniel Taylor <Daniel.Taylor-AT-wdc.com>, Jeff Garzik <jeff-AT-garzik.org>, Mark Lord <kernel-AT-teksavvy.com>, tytso-AT-mit.edu, "H. Peter Anvin" <hpa-AT-zytor.com>, hirofumi-AT-mail.parknet.co.jp, Andrew Morton <akpm-AT-linux-foundation.org>, Alan Cox <alan-AT-lxorguk.ukuu.org.uk>, irtiger-AT-gmail.com, Matthew Wilcox <matthew-AT-wil.cx>, aschnell-AT-suse.de, knikanth-AT-suse.de, jdelvare-AT-suse.de, Karel Zak <kzak-AT-redhat.com>, Jim Meyering <jim-AT-meyering.net>|
>>>>> "Tejun" == Tejun Heo <email@example.com> writes: Tejun> The [Windows Vista/7] partitioner seems to be using 1M as the Tejun> basic alignment unit and offsetting from there if explicitly Tejun> requested by the drive Yep. Tejun> Please note that hdparm is misreporting the alignment offset. It Tejun> should be reporting 512 instead of 256 for offset-by-one drives. Already fixed. Your hdparm must be old. Tejun> Partitioners maybe should only align partitions which will be Tejun> used by Linux and default to the traditional layout for others Tejun> while allowing explicit override. I don't think we take the partition type into account. Karel? Tejun> Reportedly, commonly used partitioners aren't ready to handle Tejun> drives larger than 2 TiB in any configuration and alignment isn't Tejun> done properly for drives with 4 KiB physical sectors. 4 KiB Tejun> logical sector support is broken in both the kernel Huh, what? My homedir is on a 4KiB LBS/PBS drive and has been for ~2 years. Tejun> (need more details and probably a whole section on partitioner Tejun> behaviors) I'm Cc:'ing Karel Zak and Jim Meyering who have been doing all the alignment work for fdisk and parted respectively. Karel, Jim: The full writeup is here: http://ata.wiki.kernel.org/index.php/ATA_4_KiB_sector_issues It'd be great if you guys could share what you have been doing to the tooling. Tejun> Unfortunately, the transition to 4 KiB sector size, physical only Tejun> or logical too, is looking fairly ugly. Hopefully, a reasonable Tejun> solution can be reached in not too distant future but even with Tejun> all the software side updated, it looks like it's gonna cause Tejun> significant amount of confusion and frustration. With regards to XP compatibility I don't think we should go too much out of our way to accommodate it. XP has been disowned by its master and I think virtualization will take care of the rest. FWIW, recent fdisk has a command line flag that will enable/disable DOS compatible layout. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to firstname.lastname@example.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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