Re:Scaling the box might be the real problem... (Score 1)

At NTNU (a university in Norway) we used to serve mail and homedirs (NFS) for approx. 20000 users with one HP (not sure which model) server, and one Sun Enterprise 2. This actually worked :), although a bit slow at times, and with some crashes.

We now have 2 Sun E450 servers (2 CPUs each), and are planning to get one more (4 CPUs) :) - that's overkill now - but probably not in a year or so:)

Solaris is a good choice for something like this, Sun makes big, nice servers, and the OS scales well.