Building a cluster with debian?

[Micha Feigin <michf@post.tau.ac.il>]

I'm trying to find out if it's possible to build a debian based cluster from 4
identical quad core machines that would behave as one NUMA machine?

AFAIK we have one such machine based on opetron processors in uni but I haven't
been able to find out how that is setup, i.e whether it's a hardware or
software solution. That machines shows itself as 16 cpus, which is what I would
like to achieve

I looked into kerighead and mosix variants, but it doesn't seem like any of
them can do this properly (thread migration is impossible and process migration
is problematic).

The machines are going to be all connected to every other using gigabit lan.

Thanks