Modules..

ADSM has a common pricing structure across all of our platforms, and the
pricing structure is meant to scale on the overall size of the system
setup and configured.  Thus someone using a small server setup pays a
"smaller" price than one using a larger system.

The term "device support module" is somewhat of a misnomer, and is better
thought of as a "storage expansion module".  These modules are based on
the type of devices and capacities of libraries attached to the system.
While on AIX or workstation servers, it may actually mean a new device
driver is needed (not true for every single device though!), on other
systems it is just a price feature tied to the system scalability.

Thus device module 4 (or storage expansion module 4) allows you to run
a larger instance of the ADSM server.  Its our way of maintaining a low
entry price with the ability for you to grow into bigger systems without
having to purchase a different version of the product.

Paul