*BSD News Article 21864


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Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!munnari.oz.au!spool.mu.edu!sdd.hp.com!crash!warelock
From: warelock@crash.cts.com (Tom Zacharoff)
Subject: bad144: limited to 126 by information format
Organization: CTS Network Services (crash, ctsnet), El Cajon, CA
Date: 04 Oct 93 18:41:43 PDT
Message-ID: <1993Oct04.184143.23884@crash>
Lines: 28

Hello all. I have just tried to use bad144 on my mfm hard drive to lock
out nine bad tracks (17 sectors long). I have 8192 tracks available so
having nine bad tracks seemed like a drop in the bucket. While using
bad144 I get a message:

bad144: not enough room for 17 more sectors
limited to 126 by information format

I calculated 9 tracks * 17 sectors per track = 153 bad sectors. I have too
many bad sectors to be handled by bad144. I confirmed that the bad144 table
had 126 entries in it by doing: bad144 wd0. Now if you calculate 126 
sectors that bad144 can handle times 512 bytes per sector that equals
64,512 bytes of bad disk area. That's nothing compared to the total disk
space of today's hard disks.

My question is: I have the source code to bad144. There are numerous
occurrences of the constant 126. If I change this 126 to a larger number like
some multiple of 126 will this expand the capabilities of bad144 to handle
more bad sectors? Or is this 126 something that cannot be mucked with? 

Is this 126 limit part of the dec standard 144 that is stated at the
beginning of the source code? I have already modified the installation 
script to reserve as much space I want at the end of partition e within
partition c. I have checked this and this repartitioning worked fine.

Who can shed some light on this subject? Bad144 seems to work just great
on the 126 sectors I have given it. Solid as a rock. But I need a bigger
bad144 table. Help me please!