Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!sahayman
From: sahayman@iuvax.cs.indiana.edu (Steve Hayman)
Newsgroups: comp.sys.apollo
Subject: Re: Apollo won't release rbak/wbak format.  grrr.
Message-ID: <27200@iuvax.cs.indiana.edu>
Date: 5 Oct 89 07:05:01 GMT
References: <26979@iuvax.cs.indiana.edu> <46080999.14df5@ulsoy.engin.umich.edu>
Reply-To: sahayman@iuvax.cs.indiana.edu (Steve Hayman)
Organization: Computer Science Department, Indiana University
Lines: 36

>Is knowledge of the internal format necessary?  Why
>not index the tape for a TOC?  How do you gen
>the tape in the first place?

Our Exabyte tape drive is attached to a Sun.
Right now I'm doing 
	
	wbak -stdout ... | rsh sun-with-exabyte-drive dd of=/the/tape

You can't do

	wbak -l -stdout ... | rsh sun ...

because the list-of-files-saved is written to stdout,
and vanishes down the pipe getting mixed in with the wbak stuff.

Also I don't want to create the tape over the network and then do

	rsh sun dd if=/the/tape | rbak -stdin -index


even though it would produce the index I want, because I don't want to
send all the backed-up data over the network twice (once from Apollo to
Sun to write the tape, once from Sun to Apollo to read it again and
make the index.)   This process is slow enough as it is ... I want to
run a program on the sun that will read the tape and produce a TOC.

Basically I want to do the equivalent of "rbak -stdin -index" on the
Sun itself.

Is there some obvious way to do this that I'm missing?  Anyway, I don't
see why the rbak format should be a big secret.

Steve

P.S. Thank you to Brian Holt for describing how "tar -A" works.