From: jjk1@ns1.cc.lehigh.edu (Konsultant Josh/fuzzy.happy.green.box)
Newsgroups: comp.os.msdos.misc
Subject: Re: Norton Utility's Calibrate: Is it good or not?
Date: 21 Aug 92 17:47:28 GMT
Organization: Lehigh University

In article <1992Aug21.001026.26091@nic.umass.edu>, s9874203@titan.ucc.umass.edu (s9874203) writes:
>I was told that it was always bad to do low-level format on hard disk.
>However, Norton Utility's Calibrate does such a thing. My question is: is
>Calibrate good for hard disk or not (assuming NU suggests me to have some
>optimization work done on hard disk...)? Or more simply, is low-level
>format good or not to hard disk? Thanks in advance.

Hard disks need to be formatted in two stages before you can use them:
first, they need to be "low-level" formatted (this puts down the
tracks on the disk).  Then, they need a "high-level" format; this is
different for each OS.  For example, DOS uses a FAT filesystem, OS/2
an HPFS, and Linux an inode-type filesystem.

When you low-level format a hard drive, you are essentially recreating
the tracks from scratch.  This is not bad for a hard disk in any way,
shape or form.  It is quite bad for data, as it is generally erased.
Some programs like NU's Calibrate restore the data after the reformat,
and are thus fine to use.

Finally, low-level formatting a hard drive is dependent on the
controller, drive, etc.  Calibrate will refuse to re-low level an IDE
drive because you should *never* low-level format your IDE drive.
This does not imply it is never done; the manufacturer does it for
you.  The reason has to do not with speed as someone said, but with
the way that the bad data areas are marked.  You will notice that IDE
drives never have any errors or unusable portions of the drive.  This
is because these are all automagically mapped away by the hard drive
itself (IDE hard drives have the real controller built-in; the
controller card is more a dummy than anything else, but usually
contains your floppy controllers and is thus useful :-).

The upshot of this is that if you force a re-low level on an IDE
drive, you cannot be sure of exactly what you are reformatting (since
the drive may actually be playing with a different location than you
think it is), and you can royally screw things up.  If you find that
your IDE drive is giving you tons of problems and a low-level is the
only solution you can come up with (after trying everything else),
contact the drive manufacturer.  They may be able to give you a
program - the one they originally used - which will low-level the
drive properly.

In answer to your basic question: It is not bad to low-level format a
drive unless it is an IDE, in which case it should only be your last
resort after a lengthy discussion with the drive manufacturer.  In
most cases low-level formatting an IDE drive will void the warranty
unless the manufacturer tells you specifically to do so.  Most
programs (for example, Calibrate and SpinRite II) will recognize IDEs
and refuse to nuke them.  This doesn't mean they're useless - they can
still perform pattern testing to see if new defective areas have
developed (in which case you may wish to contact the manufacturer).


-- 
____________------------===========------------____________
                     from: Josh Kopper
                      jjk1@lehigh.edu
    
  Computer Engineering, EECS Department, Lehigh University

  Systems Programming - Lehigh University Computing Center
Newsgroups: comp.os.msdos.misc,comp.sys.ibm.hardware,comp.peripherals