"dd" tape copy question

[Jeffrey W Percival]

I am using a MicroVAX II running Ultrix 3.0 and I'm trying
to copy a VMS backup tape from a 6250BPI reel to a TK50.
I tried this:

I do this:

	mt -f /dev/rmt0h rewind
	mt -f /dev/rmt1h rewind
	dd if=/dev/nrmt1h of=/dev/nrmt0h bs=10240
	dd if=/dev/nrmt1h of=/dev/nrmt0h bs=10240
	dd if=/dev/nrmt1h of=/dev/nrmt0h bs=10240
	mt -f /dev/rmt0h rewind
	mt -f /dev/rmt1h rewind
	vmsbackup -tf /dev/rmt0h

When I try using the unix "vmsbackup" reader on the copy, it gets the
volume name and saveset name right, and then says "end of tape" right away.
What magic potion is required to copy VMS backup tapes?
-- 
Jeff Percival (jwp at larry.sal.wisc.edu)