Re: Disk Geometries reported incorrectly on 2.6.0-testX

[Sven Luther]

On Sat, Nov 29, 2003 at 07:16:31AM +0200, Szakacsits Szabolcs wrote:
> 
> On Sat, 29 Nov 2003, Andrew Clausen wrote:
> > On Fri, Nov 28, 2003 at 03:24:52PM +0100, Andries Brouwer wrote:
> > >
> > > There is no such thing as a "correct" disk geometry.
> > 
> > Yes there is.  "Correct" is defined by the BIOS.  It is important
> > for boot loaders (in particular Windows).  
> 
> I suspected the same ... What Windows you mean? DOS (9x/ME/etc) or NT based
> (NT4/2000/XP/2003)? All?
> 
> > I'm not sure if this is still a big issue worth worrying about.
> 
> IMHO it might be. At least I'm getting an increasing number of emails from
> people who can't boot Windows anymore after resizing and repartitioning
> NTFS on Linux. Everybody thinks it's the Linux NTFS code's fault but so far
> it was always about the repartitioning going wrong. I just had to write a
> FAQ entry about this issue recently
> 
>       http://mlf.linux.rulez.org/mlf/ezaz/ntfsresize.html#troubleshoot
> 
> Some users, having problems, did mention the usage of 2.6 kernel. If the
> geometry changed during the fdisk, etc process then it could result also
> booting problem? It's just a speculation because I've never had enough
> information to investigate.
> 
> Also, can Parted save/restore the full and exact partition table a
> scriptable way? I mean something like this:
> 
>       sfdisk -d /dev/hda > hda.pt       # save
>       sfdisk /dev/hda < hda.pt          # restore
> 
> sfdisk can't recover geometry so apparently no one-liner, widely available,
> partition table backup/recovery is possible at present on Linux :-o
> dd if=/dev/hda of=hda.mbr bs=512 count=1 won't save the logical partitions.

Yes, that would be a good idea, it would be even nice to automatically
save the partition table the first time parted access the harddisk. The
problem is that it needs to be saved on a separate harddisk though, or
printed or something such.

The partition table saving/restoring would be part of the partition
table specific code, so you could know the logical partitions or
whatever your precise non-mbr partition table mandates.

Friendly,

Sven Luther