OK,
This begs some additional discussion.  This presumes that there is a one to
one relationship between the device class and the storage class in the TSM
environment.  But, there is probably not a single installation like that.  I
believe in this case the installation only wanted to move some tapes to the
new library, not all.  In the all scenario, changing the device class works
fine.

The issue that I see is that a storage pool in the future will need to span
more than one library simply because of the number of needed devices and
exploiting the flexibility of SANs.  I hope TSM Development is working on
this.

In our case we have two 3494s, one with 16 drives and one with 22 drives.
It is really a pain to have to worry about which library a tape will be
inserted into when it returns from the offsite storage.  It also limits us
when a SAN client is limited to one library for a storage pool of scratches
because the storage pool cannot span, but I can see how difficult it could
get to support cross library functionality.

So, I guess the only way to move from one library to another is by doing a
client move from one storage pool to another.