By enabling the EC2 Query interface and/or OCCI interface, we are opening our infrastructure to a wider audience that can lead to a higher demand of resources. This can be satisfied only by increasing our physical hardware availability.
To cope with the manageability of a larger infrastructure, we may want to split it up into smaller, independent parts to simplify its administration or to achieve partitioning for a number of reasons; these reasons will become apparent later.
For this reason, the oZones component of OpenNebula allows the centralized management of multiple running OpenNebula instances that will be called zones. This module allows the oZones administrators to monitor each zone, and enables them to grant access to the different zones to particular users, from a centralized CLI and web GUI.
In addition, inside each zone, it's possible to define multiple Virtual Data Centers (VDC) that contain a set of virtual resources (images, VM templates, virtual networks...