Re: Disk geometry changed after running linux

[David Balazic]

Guest section DW wrote:
> 
> 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").

Sorry , can't get it until saturday :-(

fdisk reports the disk geometry as 3xxxxx/xx/xx which probably LARGE.
I don't remember the start/stop cylinders of partitions.

Is there a way to change the geometry from fdisk ?
I tried expert mode and 'set sectors' and 'set heads',
but after I exit fdisk with 'w' , it is unchanged.

-- 
David Balazic
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"Be excellent to each other." - Bill & Ted
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