[Linux-cluster] Hardware recommendation

[Paras pradhan]

hi,

I will be creating a cluster using red hat EL 5.3 consisting of 3
nodes which will run Xen virtual machines. The first two nodes will
host around 30 virtual machines ( all paravirt Linux and some Solaris
if possible) . The third node will be basically a fail over node and
will host virtual machines if there is a problem at node 1 or node 2.
I do not know if this is the right way to ask but I need
recommendation on which CPU to choose (i7, phenom, quad core or dual
core) and how much RAM do I need on node 1 and node 2 and on also node
3. And also which server hardware is recommended for my purpose. My
test cluster is based on Dell Poweredge 1800 machines with DRAC 4
(which I am using for fencing) and looks like DELL Poweregde server
can be a good candidate.

Any help is highly appreciated.
Thanks
Paras.