[rhelv6-beta-list] Can RHEL6 installer align the disk partition with 4k-sector or raid stripe size?

[Steve Bonneville]

Bryan J. Smith wrote:
> > When I did the install, I *did* have the installer remove all existing
> > partitions on the disk, so that could have fixed the old partition table.
> > If I had not done that, it wouldn't surprise me to see /dev/sda1 still
> > start at LBA 63 (from the previous RHEL 5 installation).
> 
> Removing the old partition table does _not_ necessarily change the
> _existing_ geometry.  I'm sure this is done for "safety" with how
> the system might be presenting the geometry, the same geometry is
> re-used.  I'd bet on it.  One can force Anaconda to use a geometry
> though, which would solve the issue.
> 
> Best yet is to use the disk vendor's tool.  ;)
> 
> As far as documentation on the matter, these are issues with the PC and
> other OSes.  These are not Linux details.  The myriad of issues that
> have come about from endless geometry assumptions/presentations by both
> PC firmware (let alone BIOS Int13h Disk Services itself), and Windows,
> is a long history of agony and pain.

Best as I understand it, the new alignment basically does what recent
versions of Windows does, which is to ignore geometry and use LBAs to 
just align to the sector size, with a +1M offset to the start of the 
first partition.  We don't worry about breaking on cylinder boundaries
anymore, we just worry about breaking on the physical sector boundary.

That breaks compatibility with older operating systems (DOS, Windows 98,
Windows 2000) but my understanding is 2003/2008/Vista/7 all handle this
the same way.

And yeah, it's complex.  The links posted earlier are useful, the ugly
long story is at 

https://ata.wiki.kernel.org/index.php/ATA_4_KiB_sector_issues

While discussion of how to get good results with fdisk is at

http://karelzak.blogspot.com/2010/05/4096-byte-sector-hard-drives.html

> Only GPT will put an end to this suffering legacy.  ;)

Heh.

  -- Steve