Tape dumping programs for Unix/Linux... - test-drb@ccmp.vtda.org

2 May 2002

...
  From: Raymond Moyers &lt;rmoyers(a)nop.org&gt;
 To: classiccmp(a)classiccmp.org
 Subject: Re: Tape dumping programs for Unix/Linux...
 Date: Thu, 2 May 2002 16:37:30 -0500
 In-Reply-To: &lt;200205021718.g42HI9X7086853(a)daemonweed.reanimators.org&gt;
 On Thursday 02 May 2002 12:18, you wrote:
    Whats
wrong with cat ? 
 What's wrong with cat (and dd, and arguably the whole Un*x concept of
 files-as-bytestreams for that matter) is that it loses information.  A
 magnetic tape is not an ordered stream of bytes, it is an ordered
 stream of files of records, and each record has a length. 
  Here you are talking about a data tape with fields that make up records
  where the records are all the same size and the fields being varaible
  length inside the record but repeating in all the other records.
  But a tape like this, from the days when tapes was used as random
  access devices is not the format of a system archive tape is it ?
   So you are forced to result to multiple disk
files to maintain the file
 structure.
 (which adds to your hassle because now you need to manage collections
 of files instead of a single tape), 
  Like with a tarball ?
  and as you are copying the files to bytestreams
you lose the record
 length information. 
  Unless you are going to resurrect some old general ledger program
  why is this important ? 
For the same reason it is important to resurrect old computer hardware.
I thought that would be obvious to people who read this mailing list.
    carl
--
        carl lowenstein   marine physical lab   u.c. san diego
                                          clowenstein(a)ucsd.edu