Xen’s Hypervisor does not have an easy collection of performance counters. The management machine – “Domain-0″ is actually a privileged virtual machine, and thus – get its own small share of CPUs and RAM. Collecting performance information on it will lead to collecting performance information for a single VM, and not the whole bunch. “xentop” allows collection of information, however, combining this with Cacti , or any other SNMP-based collection tool is a bit tricky. A great solution is provided by Ian P. Christian in his blog post about Xen montoring and there is a script that collects the performance details.