We used the building block approach. Designing a "balanced" (we hope!)
system of a certain size. Each of these blocks can back up about 20 to 30
clients with a total disk usage of about 2 TBytes (we hope!). When we have
more clients to back up, then we add another building block - which includes
a new NT server, memory, disk cache, tape library etc.....
This spreads the load, requires less ADSM tuning knowledge, and allows easy
to understand expansion in the future.

Cheers, Chris