OpenNebula

If a VM template gets instantiated with references to non-existing VNETS (because they haven been renamed or deleted) the VM instantiates without warning or error. The resulting VM instance will simply be created without the specified nics. Especially when a VM template gets only slightly updated (change to capital, add a dash somewhere) it might not be obvious for the end user (or admin) the referenced VNET changed. In sunstone the name of the VNET is blue (You selected the following network: VNET-NAME-IN-BLUE), this could be changed to RED when VNET is non-existing. Besides that at least a warning should be issued at instantiate time. And perhaps it should not be possible at all to instantiate a template with non-existing resource references and throw an error.