[CentOS-virt] how to monitor each VM's traffic?

[Karanbir Singh]

Rudi Ahlers wrote:
> Hi all
>
> Can someone please tell me how to monitor each VM's traffic on a CentOS
> 5.2 server, running either Xen or OpenVZ? I need to bill my users for
> the traffic they use, and would like to have a traffic usage graph for
> each Xen / OpenVZ Virtual Machine on the server.

if you look at how xen sets up the Vif interfaces, you will note that 
its quite trivial. just watch the vif as you would an eth interface.