Xref: utzoo comp.unix.sysv386:728 comp.unix.misc:155
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!snorkelwacker!bloom-beacon!athena.mit.edu!jik
From: jik@athena.mit.edu (Jonathan I. Kamens)
Newsgroups: comp.unix.sysv386,comp.unix.misc
Subject: Re: Appending to archive tape
Message-ID: <1990Sep25.200757.17749@athena.mit.edu>
Date: 25 Sep 90 20:07:57 GMT
References: <732@fnx.UUCP>
Sender: daemon@athena.mit.edu (Mr Background)
Reply-To: jik@athena.mit.edu (Jonathan I. Kamens)
Distribution: na
Organization: Massachusetts Institute of Technology
Lines: 26


  Well, I don't know about the particular architecture you're working on, but
under for versions of Unix, most tape-like devices have a corresponding
non-rewinding device that doesn't rewind when it's closed (you didn't mention
this in your posting, so I don't know whether or not you know about it).

  For example, one of our machines has an exabyte tape drive hooked up to it
as /dev/mt0.  The raw device name is /dev/rmt0.  And the non-rewinding device
is /dev/nrmt0.  Last night, I wrote a tape that contained a label at the
beginning and then a tar archive.  I used:

	mt -f /dev/rmt0 rewind 
	dd if=/tmp/label of=/dev/nrmt0
	tar cvf - [files I was saving] | dd of=/dev/nrmt0
	mt -f /dev/rmt0 rewind

So, if the device you're using has a corresponding non-rewinding device, you
can use that.

  Hope this helps.

-- 
Jonathan Kamens			              USnail:
MIT Project Athena				11 Ashford Terrace
jik@Athena.MIT.EDU				Allston, MA  02134
Office: 617-253-8495			      Home: 617-782-0710