The mt -f /dev/rmt/? status will certainly tell you when
it finds a drive with a tape in it.
But also, when you do the mt -f /dev/rmt/0 fsf 1, you
should be using the norewind device, in this case:
/dev/rmt/0n, otherwise the tape will try to rewind after
the operation completes.
If it's the wrong device, you should get a message like
"No tape loaded or device offline" or
"No such file or directory".
Finally, the tar xvf command you entered was trying to
extract files FROM the tape, is that what you wanted? or
was it to backup files TO the tape, in which case you would
want tar cvf /dev/rmt/0 <files/directories to backup>
Hope this helps
Good luck
John John Philcox
Mobile Ventures Limited UK