The Carina Environment Manager is a component to handle the deployment of interconnected multi-VM application services on top of the OpenNebula IaaS platform. It supports the automated creation and run-time scaling of multi-VM application environments according to policies. It leverages the OpenNebula contextualization framework to setup clusters of VMs in a master-slave configuration or a set of workers with an IP load-balancer in front. Policies can be defined to control how VMs are added or removed based on manual, time of day, or application load-based triggers.The system will ensure that an appropriate number of VMs are started even in the presence of hypervisor or data center failures to meet application service requirements. Environments can be aggregated so that multi-tier services consisting of web, app, caching, database clusters can be interconnected and deployed as unit. A variety of sample integrations with distributed middleware and tools like Tomcat, CloudFoundry, Jenkins, HBase are provided.