International Journal of Computer Applications
Due to cloud computing, many of the traditional issues such as scale have been eliminated to some extent, but the stability, availability and reliability of cloud computing has received relatively limited attention. As cloud computing envisages "Computing as a service" it presumes 99.99% reliability as electricity grid has achieved. Reliability of a cloud computing system depends on the probability of the failure occurring in different layers of the architecture. Virtualization technique is common in cloud computing, i.e., many virtual machines even with different operating systems may be running in a single physical machine.