On Wed, Mar 10, 2010 at 12:46 AM, Arnd Bergmann <arnd@xxxxxxxx> 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-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
