Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jato!vsnyder
From: vsnyder@jato.jpl.nasa.gov (Van Snyder)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: Bad.sector.list on HD-s?
Keywords: Bad sectors
Message-ID: <1991Mar10.235310.8813@jato.jpl.nasa.gov>
Date: 10 Mar 91 23:53:10 GMT
References: <2899@hexagon.se> <1991Mar8.003618.25646@jato.jpl.nasa.gov> <13466@ccncsu.ColoState.EDU>
Reply-To: vsnyder@jato.Jpl.Nasa.Gov (Van Snyder)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 40

In article <13466@ccncsu.ColoState.EDU> sytang@lamar.ColoState.EDU (Shoou-yu tang) writes:
>In article <1991Mar8.003618.25646@jato.jpl.nasa.gov> vsnyder@jato.Jpl.Nasa.Gov (Van Snyder) writes:
>>In article <2899@hexagon.se> pa@hexagon.se (Peter Andersson) writes:
>>>
>>>Q: How do I mark them, or more specificaly,
>>>how is the list of bad sectors built. I know where
>>>to find it but not how to use/modify it.
>>
>>The SCSI protocol allows one to send a defect list with the Format
>>command.  But I don't know any low-level HD formatting programs for the ST
>>that allow you to specify the defects, so the program can put them in the SCSI
>>Format command.  Anybody out there know of such a formatting program?
>>-- 
> If you have ICD software, then you will find the program called HDUTIL, under 
> it there is a function called Map Bad disk setors. This will allow you to mark
> a sector to be bad in the FAT. And also if you used Adaptec 4070 controller,
> the bad sectors are map out by the card when it format the disk ( that's what
> I remember but not 100% certain, but do seems to recall some SCSI card map out
> the bad sectors so that the host sees the hard drive as no bad sectors).
>
I've got software that lets me mark FAT entries to indicate bad clusters, and
software that tries to discover which sectors are bad.  But the disk
manufacturer uses a more stringent test than one can do with I/O through
the SCSI.  I have an Adaptec 4000, and manual.  It's DEFINITELY possible to
tell the controller about the bad spots.  The problem is, none of the *low-
level* formatting programs I've tried know how to tell the controller about
the manufacturer's defect list.  I'd much prefer to tell the Adaptec where the
bad spots are in advance, than discover there's a bad spot in something I've
just spent 20 hours creating.  (I do backups, but not continuously).  It's the
*low-level* formatting program that's got to tell the Adaptec where the
manufacturer says the bad spots are.  Unless somebody can provide a fool-proof
(i.e. works with EVERYBODY's HD SW) algorithm for converting the "cylinder/
head/bytes-from-index" indication of bad spots into partition/cluster-number
indication.  BTW, marking FATs won't work the same way on Magic, GCR, Minix,
etc. partitions, so telling the Adaptec seems the only reliable way.

-- 
vsnyder@jato.Jpl.Nasa.Gov
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