low-level formatter for linux

[Kevin J. Cummings]

On 08/04/2009 10:13 PM, Peter Langfelder wrote:
> On Tue, Aug 4, 2009 at 6:58 PM, Markus Kesaromous<remotestar at live.com> wrote:
>> I canvassed the web looking for a linux util that will
>> low-level format a hard drive, and found noting but
>> dos and windows tools.
>> Is there a low-level HD formatter for linux?
>>
>> Markus K.
>>
> 
> How low is low? mkfs will build a file system of a specified type,
> i.e. format a partition with a given file system. It is a command-line
> utility and so low level in my book, but maybe not in yours.

Peter,
	Historically, a low-level format refers to laying down the sectors and
tracks on the disk.  mkfs is a high level formatter, building a file
system on top of the formatted tracks and sectors.

Markus,
	Since pretty much the inception of IDE disk drives, all disks are
low-level formatted at the factory, and low level formatting is not
really a user function anymore, since the formatting of the drive is
probably known to the microcode on the drive and any attempt to format
it to some other format may "break" the drive.  Most drive have the
ability to detect "bad" sectors and automatically re-map them to unused
sectors on the drive.  When the supply of unused sectors is exhausted,
the drive "dies" (ie, the bad sectors become uncorrectable errors and
those sectors are no longer usable).  Bad sectors are usually assumed to
be faulty media that cannot be "reformatted" to become good again.
It is not clear to me whether or not the firmware of modern disk drives
actually tries to reformat bad sectors before remapping them to unused
sectors.  So, you either deal with the shrinking size of your disk, or
you recover what you can from it, then throw it away and install a good one.

	What is it that you *think* a low-level formatting of the drive does?

> HTH
> 
> Peter

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)