4k sector drives

[Christoph Hellwig]

On Fri, Jul 23, 2010 at 08:09:27AM +0200, Michael Monnerie wrote:
> On Mittwoch, 21. Juli 2010 Khelben Blackstaff wrote:
> > Nevertheless, you don't have to get them to report 4k to linux. As
> >  long as you align the partitions its fine. As i said in the other
> >  post, newer fdisk doesn't use "DOS compatibility mode" and uses
> >  sectors by default (instead of stupid CHS) with a 1MB alignment, so
> >  every partition will be properly aligned. If you don't dual boot
> >  Windows, you can also use GPT partitioning scheme. Also, from what i
> >  have seen, xfsprogs are quite clever and find most stuff on their
> >  own. I usually mkfs with "-s size=4096" just to be sure.
> 
> I always do -b size=4096 anyway, so I'm fine here. And I created the 
> partitions starting sector 512, so that should be good also.

-b size=4096 is the default anyway, for 4k sector drivers you also want
-s size=4096, which you do not want for 512 byte sector disks.

What values do the files

	/sys/block/<device>/queue/logical_block_size
	/sys/block/<device>/queue/physical_block_size
	/sys/block/<device>/alignment_offset

say about your disk?