Doing multiple backups on the 6000 8mm tape

[Joe DeBattista]

Greetings,
   I'm in the process of setting up my backups on my RS/6000 model
320, version 3002.  I'd like to be able to dump all my filesystems
on the same tape, but the backup command is refusing to cooperate.
I'm trying to use the command 
   backup -0 -f /dev/rmt0.1 file_system_name

What I thought this would do would be to use the non-rewind feature
and then let me run the next backup comand for the next filesystem.
What happens, however, is that the backup command still rewinds to
the beginning before starting the next backup.  I'd be grateful for
any insights.
-- 
                            Joe DeBattista
                            ITS, UCSF Computer Center
                   BITNET:  joed at ucsfcca
                 INTERNET:  joed at cca.ucsf.edu