Path: utzoo!mnetor!uunet!husc6!cmcl2!rutgers!mtune!codas!killer!tness1!mechcrm
From: mechcrm@tness1.UUCP (Chet Murthy 713+680-8841)
Newsgroups: comp.unix.wizards
Subject: Tar with multiple volumes
Message-ID: <341@tness1.UUCP>
Date: 18 Dec 87 21:00:01 GMT
Reply-To: mechcrm@tness1.UUCP (Chet Murthy 713+680-8841)
Organization: S.W. Bell, Network Engineering, Houston
Lines: 37


Hi.  I am in the process of writing a multiple-volume tar/cpio/backup
utility.  i have already tried to build one into cpio, with moderate success -
the code is so bloody (no flames, please) messy that there's no way to do it
without a major rewrite.  So, I thought of hacking the public domain tar that
was posted to comp.sources.unix recently.  This would have the advantage
that I could freely distribute the mods.  Now, the questions:

I would appreciate any answers to these to be mailed soonest, as I will
be working on this for the next 3 weeks only.  At the end of that time, I
will probably never see this code again.

What exactly would be useful in a multivolume tape backup utility, assuming
it was based on tar?

one of the major ffeatures taht I have already had pointed out to me is the
ability to randomly access data on any tape.  That is, if the archive is
15 tapes long, and we want to get at data on the 10th tape, we don't want to
read all of the tapes 1-9.  In addition, we want a 'roadmap" which will
tell us approximately what is on each tape.  This might be a list of files
on the last tape.  Anyway, I would appreciate any information that
anybody out there could provide on this.

Also, if anybody has a copy of the POSIX standard for tar formats, could
they please Email it to me?  That way, i can understand exactly what to do
to make my mods more standard.


thanks a lot,


--chet--

Chet Murthy
Southwestern Bell Telephone, Dallas, Texas
Email: ...!ihnp4!tness1!mechcrm
       murthy@svax.cs.cornell.edu