rdump to remote Exabyte tape

[John Jorgensen]

How do I convince AIX's rdump that a remote Exabyte tape drive is big
enough hold an entire filesystem without changing tapes?

I am trying to back up an RS/6000 running AIX 3.1 to an Exabyte
hanging off a Sun 3/160 running SunOS 4.0.3.  No matter what I use as
an argument to rdump's -l option, rdump prompts me to change tapes at
about the same point in the dump.  Here's an example with a
ridiculously large -l:

  # rdump -f qucis2:/dev/xb0 -l 2000000000 -0 /usr
  The date of this level 0 dump is Thu Nov 29 16:23:23 1990.
  The date of the last level 0 dump is the epoch.
  Dumping /dev/rhd2 (/usr) to /dev/xb0 on host qucis2.
  dump: 0511-251 The file system is still mounted; data may not be consistent.
	  Use the umount command to unmount the file system; then do the dump.
  Dump is mapping regular files. This is Pass 1.
  Dump is mapping directories. This is Pass 2.
  There are an estimated 109569 tape blocks.
  Dump is dumping directories. This is Pass 3.
  Dump is dumping regular files. This is Pass 4.
  26.93% of the dump is done. It should be finished in 13:34.
  The tape is rewinding.
  Change Tapes: Mount tape number 2.
  Change tapes now.
  Please respond: Is the next tape mounted and ready? (yes:y:Y or no:n:N):

To do unattended backups overnight, I need to be able to convince the
RS/6000 that there is lots of tape left.  Has anyone managed this?

Email me, and I will post a summary.

Thanks
John Jorgensen		jorgnsn at qucis.queensu.ca	(613) 545 6784
Systems Programmer, Dept. of Computing Science, Queen's University