There are a few different ways to do this.

1)  If you have Site A and Site B then with the right high speed connection
you could backup the servers from Site A directory to 1 TSM server at Site
B.  Of course this may not be feasible if you have more data to backup in a
night then your window and the connection will allow.

2)  If you truly want a copy at both sites then I would use a copy pool but
by using virtual volumes.  Your copy pool would use a server device class
that is pointing to the other site's TSM server.  Then when you run your
storage pool backups they are put on the other TSM server.  Note that when
you do this, in a disaster you will need to DR the Site A (or first) server
at Site B.  This is because the server that stores the data only recognizes
it as archived objects through virtual volumes and not as real node date.
It is the DB from Server A that will distinguish this.

Sure you could try something with exports and imports but you are right that
doesn't make much sense.  In reality the key to the Site A and Site B
working is the connection you have between them.

Kyle Payne
payne AT berbee DOT com