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

2 May 2002

...
  Date: Thu, 2 May 2002 21:23:26 -0500 (CDT)
 From: Doc &lt;doc(a)mdrconsult.com&gt;
 To: ClassicCmp List &lt;classiccmp(a)classiccmp.org&gt;
 Subject: RE: Tape dumping programs for Unix/Linux...
 In-Reply-To: <000501c1f245$6a304ca0$1aefffcc@Shadow>

 On Thu, 2 May 2002, Douglas H. Quebbeman wrote:

  I just did a 'dd' of a bad QIC-80 tape;
it read the entire tape
 as a single file, and didn't bail out.

 I've not done that with magtape, but ISTR someone else here
 saying that 'dd' does raw reads, bad blocks and all...

 My bad if not true. 
   No bad, just an honest difference in perspective.  I recently went
 through this with a set of VMS-based diagnostics tapes.  AFAIK, the
 tapes are undamaged, but dd returns a valid read - of the first file on
 the tape - and stops.  I'm not that familiar with non-"streaming"
 formats, so I just accept what is without knowing why....
   dd on a disk or raw filesystem ignores files.  On a tape archive, even
 using the raw device as the if, dd reads files and stops at the end of
 the first record. 
I think you have your terminology mixed here.

dd reads records and stops at the end of the first file.

    carl