ABSTRACT
Grids [1] take advantage of widely available network resources and provide remote information services. They allow the network resources to be shared by users and institutions, and can provide information services remotely upon request. Current grid systems, however, provide limited separation of the service and the computing platform. They allow users to access shared network resources, but do not provide an infrastructure so that the users can customize their own private computing environments or enforce personalized policies. Recent studies show that system-level virtualization can help to solve these issues by emulating the resources and presenting a different view. In system-level virtualization the emulated resources are at the system level. A system-level virtual environment has many advantages. It allows users to work in a virtualized but familiar environment, provides an extra layer of hardware isolation and security to defend computing environments against possible attacks from malicious applications, and protects the privacy of virtual environments. Virtualization can be provided at different levels. It could be at the service level, such as grid service, at process/language level, such as Java virtual machine, or at the system level. We focus on system-level virtualization. Unless pointing out explicitly, virtualization means system-level virtualization in this chapter. The following section explains the term “system” or “system-level” virtualization.
