We have a collocated server on which we run some OpenVZ hosts. Recently, we have had to pay a lot extra we keep exceeding our bandwidth quota. Our quota is 5 Mb/s but we have spike to almost 50. I looked at the graphs and there are some spikes happening at some intervals. I want to know which process is causing this so I need a tool that monitors the processes and gives me the one with the maximum instant traffic (It doesn't matter how much traffic we have as long as we don't exceed the 5Mb/s quota). Does anyone have a recommendation for this? My hosts are CentOS 5 with OpenVZ so I can see all the containter processes from the host, if that helps in any way.