Re: [PATCH] libxfs: Get Physical Sector Size instead of Logical Sector size

Dave Chinner
2011-11-30T00:20:00Z

On Tue, Nov 29, 2011 at 11:38:33AM -0600, Eric Sandeen wrote:
> On 11/29/11 11:15 AM, Martin K. Petersen wrote:
> >>>>>> "Eric" == Eric Sandeen <sandeen@sandeen.net> writes:
> >
> > Eric> It seems that we should be checking for any alignment offsets in
> > Eric> libxfs then, too; if there IS an offset, then perhaps 4k is the
> > Eric> wrong answer, (perhaps there is no right answer) but if there is
> > Eric> NO offset, 4k should be the right choice, yes?
> >
> > In most cases the partitioning/DM tools should give you a 0 offset. But
> > it would a good idea to at least print a warning if lbs != pbs and
> > offset > 0.
>
> Right, Dave's concern was for when the partitioning tools didn't do the
> job, we don't want to break fs consistency guarantees...
>
> Dave, does checking for an offset before choosing 4k sectors seem
> sufficient to you?

Yes, especially if combined with Christoph's comments about ensure
the "-f" flag is needed to make a filesystem on an unaligned config.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com