Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mephisto!ncsuvx!news
From: map@cscosl.ncsu.edu (Mark Parris)
Newsgroups: comp.unix.ultrix
Subject: Re: Dumping multiple partitions to a single tape.
Summary: Summary of replies and success
Keywords: Dump Single Tape
Message-ID: <1990Feb21.051622.10343@ncsuvx.ncsu.edu>
Date: 21 Feb 90 05:16:22 GMT
References: <1990Feb20.054208.17932@ncsuvx.ncsu.edu>
Followup-To: poster
Distribution: usa
Organization: Operating Systems Laboratory (OSL), NCSU, Raleigh NC
Lines: 36


First of all, thanks to all of those who replied to my question.  It's nice
to be able to post a question and receive 9 (so far) answers which are in
agreement, try them, and be able to summarize within 24 hours.   Thanks.

For the summary:

The key to dumping multiple filesystems to a single tape is to use the
no rewind tape device instead of the rewind one.  In my case, this meant
using /dev/nrmt8 instead of /dev/rmt8.  That's the only thing that had
to be changed regarding dumping.  I was able to dump 3 filesystems and
restore from each using this method.  

To restore dumps of this type, use the s switch on restore (or rrestore as
in my case.)  This option allows you to specify which dump image to restore
from.   If I had dumped /usr, /usr/var, and /local to the tape in that order
and I wanted to restore from local I would use s with an argument of 3 to
specify the image of /local.

The main thing to look out for is a filesystem that spans multiple tapes.  Such
filesystems should have tapes for themselves, or at least that seemed to be
the consensus.  I have no filesystems big enough to try it out.  Be sure you
have enough room left on the tape for the next filesystem.  (The S option
on dump is handy for this.)

Someone mentioned using mt rewind to rewind the tape after all of the
dumps were made.  I was unable to test this because there seemed to be no
equivalent for remote dumps.   I simply rewound using the tape drive rewind
button.

Thanks to all who replied.

*****************************************************************************
--Explanations, suggestions, clarifying comments, and constructive criticism 
	welcome and encouraged.  /-------------------------------------------
--Flames ignored.  |-----------/   Mark Parris  map@cscosl.ncsu.edu