Document Type



Like most entrepreneurs, data center operators pursue goals like profit-maximization and improvement of the company’s reputation. Part of those aims is to guarantee a given quality of a service. These quality characteristics are specified in a contract, the so called service level agreement. The central part of this agreement are the non-functional characteristics of an IT service. The most important of these properties is the availability of the system. To comply with the requirements for availability, data center operators can use virtualization technologies. Regarding the performance of different virtualization solutions, there is still lack of easy prepared information about the different solutions. Therefore, the goal of this paper is to introduce a model, which represents the influence of features of different virtualization technologies on the availability of the data center’s IT services. At the same time, the paper points to possible problems and sensitizes for disadvantages of virtualization. Thus, the result of the paper is to improve the transparency for opportunities and risks of data center virtualization, especially in relation to system availability.