rdump from ibm 6000 to iris

[Super-User]

I would like to use rdump on a IBM 6000 to do backup on the QIC tape
drive in an Iris. Have anyone tried this ?
I get a permission denied from /etc/rmt when I try. Any help would be
appreciated
Michael Gajhede, Department of X-ray Crystallography, Chemical Institute,
Universitetsparken 5, Copenhagen University, 2100 Copenhagen Denmark.
tlf 45-31353133 ext. 250, fax 45-31350609
internet: michael at kl4iris.ki.ku.dk