1.203: How do I put multiple backups on a single 8mm tape?

There are two possible solutions to this, both of which use /dev/rmt0.1
which is non-rewinding.

SOLUTION #1
-----------

To put multiple backups on a single tape, use /dev/rmt0.1, which is a
no-rewind device, using either rdump or backup (both by name & inode
work). Using rdump or backup "byinode" both generate the message that
the tape is rewinding but actually do not. This is an example that
works on my system:

# rsh remote1 -l root /etc/rdump host:/dev/rmt0.1 -Level -u /u
# rsh remote2 -l root /etc/rdump host:/dev/rmt0.1 -Level -u /u
# tctl -f /dev/rmt0.1 rewind       # rewinds the tape

where I am implementing the command from host.
To restore a table of contents of the first I would use 

# restore -f /dev/rmt0.1 -s1 -tv

where the -s1 flag tells restore to go to the first record on the tape. 
Type the exact command again to get the second record. The -s(Number)
means go to Number record from this spot. It works pretty well.


SOLUTION #2
-----------
Steve Knodle, Educational Resources Center, Clarkson University

I use:
------------------- Dump.sh --------------------
CONTENTSFILE=`date |dd conv=lcase |sed -e 's/19//' |awk '{print $6 $2 $3}'`
set -x
LEVEL=$1
shift

backup -c -b 56 -$LEVEL -uf /dev/rmt0.1 /
backup -c -b 56 -$LEVEL -uf /dev/rmt0.1 /usr
backup -c -b 56 -$LEVEL -uf /dev/rmt0.1 /u
tctl -f /dev/rmt0 rewind

touch /usr/local/dumps/Contents.$CONTENTSFILE
echo "Dumping /" >>/usr/local/dumps/Contents.$CONTENTSFILE
restore -t -s 1 -f /dev/rmt0.1 >>/usr/local/dumps/Contents.$CONTENTSFILE
echo "Dumping /usr" >>/usr/local/dumps/Contents.$CONTENTSFILE
restore -t -q -s 1 -f /dev/rmt0.1 >>/usr/local/dumps/Contents.$CONTENTSFILE
echo "Dumping /u" >>/usr/local/dumps/Contents.$CONTENTSFILE
restore -t -q -s 1 -f /dev/rmt0.1 >>/usr/local/dumps/Contents.$CONTENTSFILE
tctl -f /dev/rmt0 rewind

I process the table-of-contents first by a little program that does
common prefix encoding, and then compress.

This gives a table of contents file I can keep on-line until the tape
is reused.


Solution #3
-----------
   mount | grep jfs | cut -c27- | cut -d" " -f1 | \
     xargs -i backup -${LEVEL} -u -f /dev/rmt1.1 {} > ${DATE}.backup 2>&1