Path: utzoo!mnetor!uunet!husc6!sri-unix!quintus!sun!decwrl!sgi!sgistl!larry
From: larry@sgistl.SGI.COM (Larry Autry)
Newsgroups: comp.unix.wizards
Subject: Re: Has tar r ever worked?  For anybody?
Message-ID: <5554@sgistl.SGI.COM>
Date: 10 Dec 87 16:17:01 GMT
References: <1344@saturn.ucsc.edu> <22121@ucbvax.BERKELEY.EDU>
Organization: Silicon Graphics, Inc., Mt.View, CA., St.Louis Ofc.
Lines: 37
Keywords: tar
Summary: an alternate method of 'tar r'

In article <22121@ucbvax.BERKELEY.EDU>, bostic@ucbvax.BERKELEY.EDU (Keith Bostic) writes:
> In article <1344@saturn.ucsc.edu>, haynes@ucscc.UCSC.EDU.ucsc.edu (99700000) writes:
> > Under 4.3BSD, has anybody ever been able to add files to an existing
> > tar tape with tar r?  When we try it the tape goes around and it 
> > appears to be doing something, but then when we tar t the files are
> > not there.
> 
On the SGI Iris 3030 'tar r' is known not to work with 1/4" tapes.
However, unless you absolutely must append to the original and only tar file
on the tape there is an alternate method.  Using the 'mt' utility if it is
available on your system, space the tape past the first tar file.  Additional
files can be added to the tape.  This accomplished by using the non-rewind 
device number as the output device.  If 'mt' is not available, try using
'tar t2'.

example: mt fsf 1
         tar cv2 .  (uses /dev/rmt2 as output)
         mt rew

and of course to retrieve;

         mt rew
         mt fsf 1
         tar xv2
         mt rew

This can be used for cpio as well.  I realize that this does not address the 
actual problem of appending to files.  It does however solve the problem of
wasting cartridge tapes by having only one file on the entire tape.


disclaimer - It worked for me on my system, good luck.
-- 
					Larry Autry
larry@sgistl.sgi.com
       or
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