This article presents an extension of the IaaS Cloud simulator CloudSim. Our CloudSim extension takes into account the processing of i/o workload generated by virtual machines within a Data Center and evaluates the overall performance and energy consumption. Indeed, storage systems energy consumption may represent up to 40 % of the total energy consumed in a Data Center. Then, we propose three contributions. First, we modified the time computation model of CloudSim to consider i/o operations. Second, we designed several models of storage system devices including Hard Disk Drives and Solid-State Drives, and finally, we considered the cpu and ram used for i/o request processing. Our extensions have been evaluated using video encoding traces. First simulation results showed that a significant amount of energy, around 17 %, is consumed due to I/O workload execution, which shows the soundness of our CloudSim extensions