During the last years, virtual machine technologies have become more and more widespread. Possible virtual machine integration is on the cluster grid computing environment. So, the implemented idea described on this paper is based on virtual machine computing service. For these reasons, the main purpose of this research is to validate integration functionalities and performances of a load balancing system into a cloud grid with virtual compute servers. Tests have focused on the restart of a batch job after a hardware crash and on the stopping of a job or its transfer to another host for hardware maintenance.