Re: a (late) question concerning the CHS disaster ...

[Sven Luther]

On Fri, Dec 03, 2004 at 02:55:27PM -0500, Patrick J. LoPresti wrote:
> Sven Luther <address@hidden> writes:
> 
> > Well, when we use blank disks, there is no problem, because windows
> > is not installed on it, right ? And if windows then fail, it is
> > windows fault.
> 
> If you later install Windows, you will encounter problems.  This is
> why I took an interest in this stuff in the first place (see
> http://unattended.sourceforge.net/).

Bah, ...

> > As for machines where disk has been moved, i don't get it. the
> > partition table is on disk, so using it is always ok, even if the
> > disk was moved.
> 
>   1) Move disk between machines
> 
>   2) parted /dev/hda
> 
>   3) mklabel msdos

You erased the whole disk, so anything you have done in the previous machine
is forgotten and you don't need to care about it.

>   4) mkpart ...
> 
> What geometry will/should Parted use?

Anything parted thinks is sane. Preferably something windows will be happy
with, if we can find such a geometry, but as such a geometry seems to be
non-deterministic in general ...

> > > To my knowledge, there is still no way for me to tell Parted what
> > > geometry to use.  Which is frustrating, because I (or rather, my code)
> > > actually knows.
> > 
> > Well, you can simply open the device and overwrite bios_geometry,
> > not ?
> 
> My code is in Perl, invoking the parted binary with the "-s" switch.
> I read /sys/firmware/edd/int13_dev80/legacy_* to figure out the
> geometry to use.  I write to /proc/ide/hda/settings to convince the
> kernel to return that geometry for HDIO_GETGEO.  I wipe the partition
> table in a separate step so that Parted will actually use that
> geometry instead of guessing.

I don't understand, there is this nice libparted library, so why in hell are
you calling the parted binary directly ? I believe there is even a perl
binding for libparted.

> And it works.  But it is so messy...  And the Linux folks are
> threatening to remove HDIO_GETGEO.

Yeah, well, nothing i can do aboutthis ...

Friendly,

Sven Luther