We have a 3494 tape library shared between our TSM server and our
z/OS system. It contains a mixture of 3490, 3590, and 3592 tape
volumes. Our insurance company is pushing us to install a fire
suppression system inside the 3494. The planning manual for the
3494 has detailed information on the space available for fire
suppression hardware, but no information on the pros and cons of
different extinguishing agents.

We have a halon system protecting other parts of the machine room
complex. It is not immediately clear whether it would be legal to
add piping to extend the system's coverage to new areas.

If extending the halon system is legal, is this the best choice?
If it is not legal, what is the best alternative?