FDisk won't detect or accept correct disk geometry from BIOS
hhasenbe at techfak.uni-bielefeld.de
Fri Jan 23 01:55:53 PST 2004
Keith Kelly wrote:
>>OK, but if the auto mode uses the wrong C/H/S translation, this default
>>may be the source of your problem. What happens when you switch from
>>using "auto" to explicitly using "LBA"?
> I don't know. I've never had to change away from "Auto" to get any other OS
> to install or boot from any of my hard drives, though, so I really doubt
> that is the problem. I'm quite confident the problem must lie with FreeBSD
> itself, in the form of a bug or a lack of hardware support. Although my
> integrated IDE controller and all other basic hardware is on the FreeBSD
> supported hardware list.
No, the problem doesn't lie with FreeBSD. The problem is in the long
line of kept compatibilities since the first Intel-PC. There is no need
for an addressing mode besides LBA if you are using current hardware
(And this current being a long time). The problem first came when the
hard drives hit the first CHS barrier: The manufacturing companies chose
different formulas to converted the real CHS to the BIOS CHS values. So
until the get used to a common formula or the Linear Block Adressing you
couldnt even swap harddrives from one system to another of another IDE
board manufacturer. SCSI got more luck on this platform since most
manufactures used the adaptec formula and NCR had its own, but could
detect if an adaptec formula was used. Back to your systems problem. The
BIOS assumes you a different alignment on the harddrive than the system.
ONLY if you choose ONE addressing mode you get predictable results and
that should be LBA, since it is used in modern ATA-commands. Other
addressing modes should only be used for older drives which cant use
LBA. I hope there will be a time when the CHS conversions get dropped
from BIOS, but I doubt that. Choosing one mode enforces the correct
conversion on each system.
>>>I definitely do not have hardware issues, because Linux, Windows XP,
>>>2000, BeOS, and SkyOS have all worked fine at various points, and
>>>continues to work fine :-)
Lucky you. Haven't been so lucky, but LBA solved it.
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