Re: Disk geometry changed after running linux

[Guest section DW]

On Mon, Jan 15, 2001 at 07:18:30PM +0100, David Balazic wrote:

> Then I installed linux ( "some" beta version , kernel
> is some recent 2.4.0-testXX )
> 
> After the installation the disk ( win2000 ) would not boot.
> It reports :
> Read error on disk.
> Press ctrl+alt+del to reboot.
> 
> If I run linux ( it work OK from the boot floppy ),
> it reports the geometry as 3xxxx/??/??.
> Thirty thousand and some cylinders , H and S are probably 16/63
> ( don't have it at hand ).
> 
> It should be two thousand something and 255/63, I think.
> 
> fdisk -l /dev/hda prints "Partition 1 does not end on cylinder boundary"
> messages for the NTFS partitions ( hda1 and hda5 ). The linux ones are
> OK.
> 
> The problem is that now the BIOS sets Access mode to LARGE.
> I can workaround it by changing access mode in BIOS setup
> from AUTO to LBA, but I want to know what made BIOS to default to
> LARGE and how to fix it.

Since "disk geometry" has become such a terrible mess,
recent BIOSes decide that they don't know what the geometry
should be, and guess the geometry from the partition table,
if there is one.

So, if you added partitions during the install then it is
not impossible that the BIOS changed its mind concerning
the geometry.

It would be interesting to see the precise partition table
(output of "fdisk -l /dev/hda").