Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!munnari.oz.au!brolga!bunyip.cc.uq.oz.au!marlin.jcu.edu.au!zlraa
From: zlraa@marlin.jcu.edu.au (Ross Alford)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: 2 PC Questions
Message-ID: <1991Feb9.053542.508@marlin.jcu.edu.au>
Date: 9 Feb 91 05:35:42 GMT
References: <1991Feb7.224045.10886@pa.dec.com> <1991Feb8.043253.22719@magnus.ircc.ohio-state.edu>
Organization: James Cook University of North Queensland
Lines: 48

In article <1991Feb8.043253.22719@magnus.ircc.ohio-state.edu> smsmith@hpuxa.ircc.ohio-state.edu (Stephen M. Smith) writes:
>yip@wsl.dec.com (Michael Yip (Lt Cmdr - Chief Test Pilot)) writes:
>>A friend of mine called me up a couple of days ago with some
>>problems on her XT compatible...  
  ... (basically, her hard disk periodically refuses to boot)...

>... My suspicion is
>that it has been a LONG time since she did any disk optimizing, and
>over time the heads in the disk have drifted so that when the disk
>has run for a while the slight expansion in the disk causes the heads
>to misalign with the sectors.
>
>Have her back up the files onto floppies with copy or xcopy, then 
>low level format the disk and reinstall the operating system, then
>put the files back on.  By using the "copy" or "xcopy" command, the
>files will then be written back on the disk in contiguous sectors
>and therefore her hard drive will be automatically optimized.
>
A couple of comments:  

First, I've had this problem myself.  After about
2 years, the heads on a some hard drives seem to slowly lose their
mechanical alignment, so the disk has trouble finding sectors,
particularly when booting.  Backing up (twice is a good idea if you've
got the patience) and doing a low-level reformat, so the tracks and
various marks are in the positions the heads expect to find them in
their current mechanical alignment, does seem to cure this sort of
problem.  

Second, for goodness' sake don't bother using copy or xcopy to
do your backup.  I don't know of *any* DOS backup utility, either the
MSDOS standard or any of the various independently supplied ones (e.g.
Mace, Fastback, PC-Tools, ...) that actually does an image backup when
backing up to a floppy.  They *all* read and write a file at a time.  It
doesn't look that way on the backup disks because they stick the
information from each file to the tail end of the information of the
preceding file, and use their own internal indexing to keep track of
where one ends and the next begins.  Doing a backup and restore with any
of these programs will lead to all files being contiguous on the hard
disk, and will be a lot less trouble than using copy or xcopy.  

Ross Alford
zlraa@marlin.jcu.edu.au
-- 
//DUXYZY01 JOB DU.D00.AA1234,ALFORD
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// DISP=(NEW,CATLG),SPACE=(TRK,(10,,10),RLSE),UNIT=DISK,VOL=SER=DUK333  ... ACK!