How to change LBA48 addressing capability

[Dan Hensley]

On Tue, 2008-07-08 at 16:28 +0100, Bill Crawford wrote:
> 2008/7/8 Dan Hensley <dan at dshensley.com>:
> > I recently sent an inquiry to this list about fdisk being unable to seek
> > one of my two basically identical disks.  Both are Western Digital 250Gb
> > disks.
> >
> > Unable to seek on /dev/sdb
> >
> > This disk operates just fine when booting Fedora Core 6.  However, as
> > soon as I boot Fedora 9, I get the above error.  testdisk seems to
> > think /dev/sdb is only 137gb, and hdparm confirms something strange.
> 
> There are two other possibilities: a jumper on the drive is "clipping"
> its capacity, and / or the presence of a "host protected area"
> effectively doing the same thing. Check for jumpers on the drive, see
> if the "libata.ignore_hpa=1" option is still supported by the current
> kernel.

There are no jumpers on the drive, and I don't think I've ever had one
on there.  I just checked the documentation on the drive, and since it's
an SATA drive the jumpers are for unrelated options.  Unfortunately the
libata.ignore_hpa=1 option doesn't seem to be supported by the kernel.

I'm pretty sure this is a kernel bug.  This drive worked flawlessly in
FC6.  It still works in FC6, because that's what is on that drive, and I
can still boot to it.  Only when I boot into Fedora 9 does this drive
map incorrectly.  So it appears that something broke between 2.6.22 and
2.6.25.

Dan