The virtualized systems are one of the key elements of the next generation IT infrastructures. Modeling it will prevent mistakes, and oversized management. Opennebula is one of the most current open source cloud management solutions. Together with Haizea, they are a powerful tool to model and manage a virtualized infrastructure trough the API of Openebula. Haizea has multiple scheduler algorithms that are more effective than that of Opennebula. We performed several experiments to compare simulation and measurement capabilities of Haizea and we highlighted some difference between them which can be reduced if required.