Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!kramden.acf.nyu.edu!brnstnd
From: brnstnd@kramden.acf.nyu.edu (Dan Bernstein)
Newsgroups: comp.unix.questions
Subject: Re: Backups using compress
Message-ID: <26547:Dec404:51:1690@kramden.acf.nyu.edu>
Date: 4 Dec 90 04:51:16 GMT
References: <27551FBF.2222@tct.uucp> <11389:Nov3010:16:4190@kramden.acf.nyu.edu> <275A875A.3AB0@tct.uucp>
Organization: IR
Lines: 20

In article <275A875A.3AB0@tct.uucp> chip@tct.uucp (Chip Salzenberg) writes:
> According to brnstnd@kramden.acf.nyu.edu (Dan Bernstein):
> >In article <27551FBF.2222@tct.uucp> chip@tct.uucp (Chip Salzenberg) writes:
> >> I would think twice before using this method for backups.  LZW
> >> compression (i.e. /usr/bin/compress), like most kinds of compression,
> >> is _extremely_ unforgiving of trashed data.  If you lose ONE BYTE, the
> >> rest of the archive will probably be lost permanently.
> >If you want to correct errors, use an error-correcting code.
> Sure, error correction is very nice.  But sometimes data are lost,
> period, no recourse, from the *middle* of a backup.

So what? Do you mean to say that error-correcting codes can't correct
errors?

``But if someone bombs your computer center and all your offsite storage
locations then you probably won't be able to recover the backup.''
Great, Chip. I think I'll waste half the space on every tape just in
case that happens.

---Dan