You will be using the export node / import node feature of ADSM to do this.
Sort of a pain in the butt, but doable.  As long as the media format, i.e.,
DLT or 3590, is common between your existing server and the new one, you'll
be ok.  I wouldn't wait until I had 16 TB of data on the NT server before I
moved.  I'd move now if you're going to move.  Waiting won't make the
process any easier.

Kelly J. Lipp
Storage Solutions Specialists, Inc.
PO Box 51313
Colorado Springs CO 80949
719-531-5926
www.storsol.com
lipp AT storsol DOT com