just imaging ...

can you build a hierarchical system ?

many dumb X-terms (x-servers) ...

several idendical application server
(maybe sharing the same hd image via high spped nfs mounts)

(addresses with the same ip with RR dns, or on different LAN to pation traffic)

a "big" file (mail, http, database) server backend,
accessed only by middle tier machines?

more scalable ?

.