I am having problems backing up a filesystem onto tape using the vxdump command:

# vxdump -0uf /appl /dev/rmt/0n

What I want to do is to backup the /appl files onto tape
I keep getting error message:
Error: I/O # vxdump -0uf /appl /dev/rmt/0m

vxfs vxdump: read of super-block on /dev/rmt/0m failed: I/O error

Can anyone help me out with this one?

Ben P