I agree with David.  Overflow is pretty much the only option I see.  That,
or get rid of your copypools. Heh.

There's some good information in the Admin Guide.  In the 4.2 Admin Guide
(AIX), Chapter 7, "Managing Removable Media Operations," a section is
"Managing a Full Library."  It's on page 97 for me.  I hope that helps.

Alex