Re: ATA 4 KiB sector issues.

[Nikanth Karthikesan <knikanth@suse.de>]

On Thursday 11 March 2010 19:58:11 Theodore Tso wrote:
> On Mar 11, 2010, at 8:57 AM, Nikanth Karthikesan wrote:
> > I guess, what he meant was, to keep filesystem blocks aligned, even if
> > the partition is not. Say if the partition is mis-aligned by 512-bytes,
> > let the filesystem waste 4k-512bytes and keep it's blocks aligned. But it
> > might be a case of over-engineering, possibly requiring disk format
> > change.
> 
> Ah, yes, I agree with you; that's probably what he meant.
> 
> Sure, that's theoretically possible, but it would mean changing every
>  single filesystem, and it would require a file system format change --- or
>  at least a file system format extension.
> 
> It would seem to be way easier to simply fix the partitioning tools to do
>  the right thing, though.
> 

Yes. May be, just a simple but transparent device-mapper like mapping on top 
of the mis-aligned partition, to do the alignment. Then the file-system code 
need not change much.

But Linux already has device-mapper and Linux will not be affected with mis-
aligned partitions, when we use LVM.

But the actual problem here is that partitioning tools might create partitions 
that wont allow other operating-systems to boot. So it might be enough, if the 
partitioning tools just create partitions with (mis-)alignment requirement for 
Windows.

Thanks
Nikanth