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From: paula@bcsaic.UUCP (Paul Allen)
Newsgroups: comp.unix.questions,comp.unix.microport
Subject: Re: dump/restore
Keywords: multiple volume backups
Message-ID: <8463@bcsaic.UUCP>
Date: 1 Nov 88 01:31:56 GMT
References: <178@celerity.UUCP> <229@dcs.UUCP> <180@celerity.UUCP>
Reply-To: paula@bcsaic.UUCP (Paul Allen)
Organization: Boeing Computer Services AI Center, Seattle
Lines: 22

Several people have complained that tar cannot write multi-volume
backups.  While the use of tar for backups may be debatable, it is
fairly simple to write a multi-volume tar archive.  The basic idea is
to pipe the tar output to a script that has a loop containing a prompt for
the next {tape,disk} to be mounted and a dd command to copy just the
right number of blocks from stdin to the device.  I use something
similar to this in my unattended-dump-to-disk scheme, and it works quite
nicely.

Several other complaints about tar have been voiced during this
discussion.  I would suggest that people get a copy of John Gilmore's
public domain tar program.  It's in the archives.  It supports strange
things like named pipes and devices.  It has limited support for reading
a damaged archive.  It can take a list of files to copy from stdin.
If dump/restore are not available, this program is a reasonable
alternative.

Paul Allen

-- 
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Paul L. Allen                       | paula@boeing.com
Boeing Advanced Technology Center   | ...!uw-beaver!ssc-vax!bcsaic!paula