Dependability modeling and analysis for the virtual clusters

The modeling and dependability analysis of virtualization system is always challenging due to the particular characteristic and mechanism of virtualization, in this paper we attempt to modeling virtual clusters using a hierarchical method combining a upper-layer Reliability Block Diagram (RBD) model and a lower-layer Markov model. Taking into account both the failure of physical servers and the virtual machines, the Markov model for one cluster is established while the RBD model reveals an overall structure of virtual clusters as well. The dependability of which three attributes are concentrated including availability, reliability and maintainability in this paper, is then theoretically analyzed by solving the proposed hybrid model, some useful advices are suggested to design an effective virtualization system with required dependability in according to the numerical results.