Improving machine virtualisation with 'hotplug memory'

Machine virtualisation is a key technology for server consolidation and on-demand server provisioning. To support this trend, it is essential to improve the performance of virtualisation software and enable the efficient running of many virtual machines. We present a virtualisation system that can dynamically extend the real memory of its guest virtual machines. We describe an implementation of dynamic memory extension for Linux guests running on the IBM zVM virtualisation environment. Our implementation utilises device drivers for accessing dynamic memory extensions. We show that this capability can improve utilisation and performance of the Linux guests in our virtualisation environment. © 2008, Inderscience Publishers.