XtreemOS: a Sound Foundation for Cloud Infrastructure and Federations

Abstract XtreemOS is a Linux-based operating system with native support for vir-tual organizations (VO’s), for building large-scale resource federations. XtreemOS has been designed as a grid operating system, supporting the model of resource sharing among independent administrative domains. We argue, however, that the VO concept can be used to establish either resource sharing or resource isolation, or even both at the same time. We outline XtreemOS ’ fundamental properties and how its native VO support can be used to implement cloud infrastructure and cloud federations. 1 XtreemOS Developing and deploying applications for traditional (single computer) operating systems is well understood. Federated resources like in grid environments, however, are generally perceived as highly complex and difficult to use. The difference lies in the underlying system achitecture. Operating systems provide a well-integrated set of services like processes, files, memory, sockets, user accounts and access rights. Grids, in contrast, add a more or less heterogeneous middleware layer on top of the operating systems of the federated resources. This lack of integration has lead to a lot of complexity, for both users and administrators. To remedy this situation, XtreemOS [7] has been designed as a grid operating system. While being based on Linux, it provides a comprehensive set of services as well as a stable interface for wide-area, dynamic, distributed infrastructures com-posed of heterogeneous resources spanning multiple administrative domains. The fundamental issues addressed by XtreemOS are scalability and transparency