C12G has created a new article to describe how to extend the OpenNebula monitoring system. OpenNebula needs to monitor the physical resources known to the system in order to extract information that in turn is used by the scheduler to enforce (and comply with) placement policies, keeping the host capacity from being overbooked.
The Monitoring System in OpenNebula follows the design guidelines present in the rest of its architecture, including the modularity present in other components. This modularity is expressed in this case in a plugin approach, where the information is extracted using ‘probes’, basically simple scripts that return pieces of wanted information.
This new howto shows how to extend the Monitoring System to extract information about disk space availability, and then use it in the Virtual Machine templates to ensure the presence of enough disk space for the image in the chosen host to run that Virtual Machine.