Date Added: Sep 2011
Virtualization has recently become a very popular technique for utilizing hardware capabilities and lowering infrastructure and maintenance costs. However, making several virtual machines share the same resources can potentially introduce performance isolation problems. Depending on the application, proper quality of service and the performance isolation may present critical requirements for the system. In this paper, the authors focus on network performance isolation among virtual adapters in Xen. They present several experiments demonstrating how activity of one virtual machine can affect the network performance of any other. Additionally, they examine the network I/O scheduler in Xen to see if it is fair, predictable and configurable enough. Finally, they propose an idea on how to modify Xen back-end drivers to improve the network performance isolation.