[CentOS] OT: Recommendations for a virtual storage server

Hi all,

  I need to install a virtual machine acting as a virtual storage server under 
CentOS 5.x (using kvm, xen, virtualbox or vmware). This virtual storage machine 
needs to server storage to another ESXi server and at the same time to the host 
where is installed.

  This is due to the limitations of hardware I have available. Both hosts needs to 
server several machines.

  It is very important that the virtual machine consumes the least resources 
possible (host has 5GB RAM and i need to run three virtual machines minimum, 
including this storage server as a virtual machine).

  What can be better solution: CentOS, NexentaStor, openfiler ...??

  Many thaks.
-- 
CL Martinez
carlopmart {at} gmail {d0t} com