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From: rad@masscomp.UUCP (Bob Doolittle)
Newsgroups: comp.sys.amiga
Subject: Re: hard disk flaw problems
Message-ID: <2605@masscomp.UUCP>
Date: Sat, 21-Nov-87 13:41:47 EST
Article-I.D.: masscomp.2605
Posted: Sat Nov 21 13:41:47 1987
Date-Received: Wed, 25-Nov-87 20:30:05 EST
References: <1884@cadovax.UUCP>
Reply-To: rad@masscomp.UUCP (Bob Doolittle)
Organization: MASSCOMP - Westford, Ma
Lines: 42
Keywords: hard disk format flaws

In article <1884@cadovax.UUCP> kaz@cadovax.UUCP (Kerry Zimmerman) writes:
>[]
>The good news was that a friend gave me his spare Fujitsu M2243AS
>hard disk drive.  This baby has a formatted storage capacity of 
>67 megabytes! YUMM.
>The bad news is that I can't get it to format with my A2090 controller.

I have heard from my local service rep that you can't tell the 2090
about a disk with greater than 50Mb capacity :-(.  Maybe the new FS will
solve this problem (let's hope).  He said you must fool the formatter,
by reducing the number of cylinders to make your disk look like a 50Mb,
then you can at least use that much.

>2.  How do you add new flaws to the flaw map?
>    Isn't there a way to add additional flaws
>    to the flaw map, should they appear, without using prep?

I don't think you can do this under UNIX, either.  You must back up,
reformat, and restore your disk (which is what I did).  Diskdoctor does
work on hard disks (just specify dh0:), and will facilitate your backing
up.  I'm not sure just what diskdoctor does exactly - it finds bad
cylinders, and removes files which reside on them.  My question is, does
it somehow leave the questionable blocks off the free list - giving you
a clean file system?  Or is this just so that all remaining files are
readable so you can grab what's left.  I suspect it removes more files
than it needs to.  I think it trims an entire cylinders worth, rather
than pinning it down the the specific bad block on that cylinder.
Still, better than nothing, and good for the short term.  If you've got
an intelligent backup program that won't choke on bad blocks (MRbackup
1.3 fails here) you're better off.

>3.  Why does the format retry so much?  It seems to be wasting its time
>    going for fifteen minutes on the same cylinder.  And, why does it
>    quit instead of going to the next cylinder?
I think this is all due to the 50Mb limit.  Not a particularly graceful
or informative error message :-|.

-- 
Once in a while
you get shown the light		UUCP Address:
in the strangest of places	    ...!{ihnp4,seismo,ucbcad,gatech}!masscomp!rad
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