dhcp virtual server .
 

how to create dhcp server in a virtual centos machine?and how to manage it to affect an ip addresses to physical hosts?

there is *NOTHING* interesting about runing DHCP on a virtual machine, treat it like any other server. Only design aspect would be to use bridged networking, not NAT when the VM is created.

if the virtuall machine is qemu-kvm how can i do that?

do what??

It may be easier to consider almost any virtual machine as if it were a real computer.

The only issue is usually using bridged or nat connection. For this case, I think I might use bridged.