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Date: Thu, 20 Oct 2016 11:44:50 +0200
From: Polytropon <freebsd@edvax.de>
To: jd1008 <jd1008@gmail.com>
Cc: freebsd-questions@freebsd.org
Subject: Re: Drive Read Errors
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On Wed, 19 Oct 2016 18:20:57 -0600, jd1008 wrote:
> It would be very useful if users were allowed the option to re-run
> very low level format to remove all bad blocks from the "good" blocks
> map, and create a new set of good blocks for future bad block replacement.
> But of course, that would reduce the capacity (size), which would 
> require that
> such information be available to the computer.
> 
> But of course, manufacturers are not interested in "extending" the 
> usable life of a drive :)

Are you old enough to remeber the time when the PC's BIOS
(AMIBIOS at least) had the options

	LOW LEVEL FORMAT

and

	MEDIA ANALYIS

combined with the ability to manually specify the disk
geometry in C/H/S format ("type 47") - where you could
enter _smaller_ values (resulting in less disk space of
course) in order to "circumvent defective sectors" when
they were located at the "end of the disk"?

                                  Cyln  Head  WPComp  LZone  Sect  Size
Disk C: Type   : 47 = USER TYPE   976   12    65535   976    61    349 MB
Disk D: Type   : Not installed

Looks familiar? :-)

I still have an 80 MB (P)ATA disk that has been "down-
formatted" to 40 MB which actually works! It's part of
my timeless museum of impossible things. :-)



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...