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From: rmk@rmkhome.UUCP (Rick Kelly)
Newsgroups: comp.unix.sysv386
Subject: Re: Mapping abs sector numbers to files
Message-ID: <9106171448.32@rmkhome.UUCP>
Date: 17 Jun 91 23:48:00 GMT
References: <1991Jun10.134714.28189@virtech.uucp> <1055@dumbcat.sf.ca.us> <1991Jun14.181849.3725@newshost.anu.edu.au> <1058@dumbcat.sf.ca.us>
Reply-To: rmk@rmkhome.UUCP (Rick Kelly)
Organization: The Man With Ten Cats
Lines: 29

In article <1058@dumbcat.sf.ca.us> marc@dumbcat.sf.ca.us (Marco S Hyman) writes:
>In article <1991Jun14.181849.3725@newshost.anu.edu.au> cmf851@anu.oz.au (Albert Langer) writes:
> > Sorry if I have misunderstood this thread. My understanding is that
> > SCSI drives normally map out bad sectors themselves and neither report
> > defects to the operating system nor make use of a manufacturer's defect
> > list. If that is wrong, somebody please tell me. If it is right then
> > the discussion seems pointless unless I have misunderstood it.
> > 
> > (I am assuming that AHA 1452 is a typo for AHA 1542 SCSI host adaptor).
>
>Yep.  The SCSI controller is a 1542A.  Using 386/ix 2.0.2 and a pair of
>Seagate 80 MByte drives (I forget the number) I get hard errors reported to
>the console.  Automatic mad sector mapping is NOT performed.  This is a GOOD
>thing as the hard errors are usually (more than 98% of the time) not hard
>errors. That is I can copy files, get errors on the original file, look at
>the copy, and find nothing wrong.  I suspect the cheap Seagate drives -- or
>the fact that I'm running two of them.
>
>The last time I mapped out a bad sector by hand I lost a chunk of the
>/usr/lib/news directory.  (I always wait until after doing a full backup
>before mapping anything out).  Think of the problems that would occur of this
>happened automatically.


However, most SCSI drives can be modeselected to do auto bad sector mapping.
But, as you say, this isn't the most desirable option.  The Bernoulli box
does this by default.

Rick Kelly	rmk@rmkhome.UUCP	frog!rmkhome!rmk	rmk@frog.UUCP