[lug] redhat install

[Peter Hutnick]

On Friday 12 July 2002 09:26 am, J. Wayde Allen wrote:
> On Thu, 11 Jul 2002, j davis wrote:
> > its ide :(  was a brand new w.d.40 gig right out the box....I have
> > installed before without preformating my disk....
>
> I was referring to the low level formating of the drive
> <http://www.webopedia.com/TERM/L/low_level_format.html>.  For IDE disks
> this is done at the factory.  If somehow that got screwed up I think you
> have a definite problem.  Usually SCSI controllers have the ability to
> create a low level format.  I'm not aware of such capability in IDE
> controllers, but there may be a way.

"Low Level Formatting" on IDE is a source of a lot of confusion.

The first thing you should understand is that modern disks use "embedded 
servo data" which means that they use read-only "mile markers" on the disk 
instead of a stepper motor.  The effect is that the drive continues to work 
reliably even if there is a significant change in temperature.

If this data is erased the drive will not work.  When embedded servo was 
introduced in IDE a lot of misunderstandings resulted.

First, be aware that NO normal IDE command(s) can cause this data to be 
overwritten.  Period.  A special, disk dependent code /can/ be used to 
cause the disk to perform a LLF using a routine on the controller firmware.  
Unless the maker of your disk is a retarded this won't damage the servo data 
either.

Bottom line is that, contrary to popular opinion, you can't break an IDE disk 
with software.

In a previous post I suggested making sure you are on a recent version of 
your BIOS in passing.  I'd like to re-emphasize that, as I have seen a couple 
of notes to the effect that a disk type mismatch (that is, if your system is 
set up for x, y, z sec, cyl, hds and the disk is actually l, m, n the BIOS 
will give a DMI related message.  Linux doesn't care how "right" this setting 
is, as long as the boot partition is accessable (and I think this requirement 
goes away with GRUB).

Good luck!

-Peter