[Beowulf] Virtualization

[Mark Hahn]

> interested in finding out about virtualisation on beowulf. The pros
> and cons, what software can be used and the limitations of such
> software.

virtualization does, inherently, sacrifice some performance.  since 
beowulf is often motivated by achieving higher performance, this is 
somewhat contradictory.

> Can a beowulf cluster be applied to cloud computing? Will it run xen

afaikt, "cloud computing" means

<handwave speed=vigorous> lightweight clients interacting through random,
loose, disparate connections with service-providing things over some 
kind of soap-ish, webby protocols </handwave>

so sure, why not?  CC is mainly about not requiring any particular
design or structure, so sure you could host your clients and servers
inside VM's under a cluster.  I'm not sure I'd call it a beowulf cluster,
though.

> or vmware or would an operating system-level virtualization package
> such as open VZ be more suitable.

I can't see that it would make any difference.  actually, I'm not sure
there would be any real need to use a VM or other container at all:
a cloud server is basically just a service definition and some sort of 
IP connectivity.  they could run as normal jobs on a cluster (with no
virtualization or containment.)

> most of all, what's scalable?

virtualization is no friend of performance scaling.  or do you mean 
human-effort (TCOish) scaling?  I'd guess the most human-scalable 
approach would be one big SMP, or at least a few very fat nodes.