On 3/12/21 2:59 PM, Eric Auer wrote:
Hi Jon,

actually I do not expect "drivers" like OnTrack, Ez Drive etc.
to mess with host protected areas.

It's not OnTrack that I think is messing with the HPA, it's the
SATA <-> IDE adapter. Because when I boot from the OnTrack
installation floppy, I find that the disk in question shows up
with a reported *physical* (not paritioned) size of 130 MB.

This is the same size that a Linux Live CD shows for the disk,
even though the kernel version on the disk is recent enough that
it only pays attention to what the disk tells it and completely
ignores reported BIOS values.

So I have two software packages (Linux and OnTrack) which are
known to ignore the geometry that BIOS gives them and ask the
disk directly (that's the entire *point* of OnTrack), and both
of which are known to be able to handle disks (much) larger
than 130 MB, and both are reporting the same bogus disk size
as BIOS is giving (whereas Linux, at least, gives a correct size
for the drive with the same adapter on a machine whose hardware
and BIOS are about 5 years newer). My conclusion, then, is that
some sort of pathological interaction between the BIOS and the
adapter is happening that's causing the adapter to set an HPA on
the drive, with the result that the drive reports a bogus capacity
when Linux/Ontrack gets control of the machine and starts querying
the drive for its size, and also refuses I/O to addresses beyond the
HPA limit. Most likely, I think is that the adapter is seeing a
certain pattern of ATA commands from the drive that indicates to it
that the BIOS is having trouble with the size of the drive, and
is "helpfully" setting an HPA to cripple the drive down to whatever
it thinks the BIOS can handle (which turns out being less than the
biggest drive geometry the user can manually set in BIOS, which is
in turn less than the biggest geometry the BIOS can auto-detect).



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