If you are looking to run VMware ESXi servers through OnApp, then you will require an external installation of vCenter. These can be installed on virtual servers, if necessary, but should not be hosted inside OnApp. 

The OnApp Control Panel server communicates with vCenter over the OnApp management network.

The following are the requirements for VMware integration with OnApp Control Panel:

  • vCenter ESXi hosts must be organized into Clusters.

  • All of the ESXi hosts must be added to a vSphere Distributed Switch.
  • At least one datastore on the ESXi hosts is required for the virtual server provisioning. Make sure that this datastore is accessible to all ESXi hosts in a Cluster. NOTE: The datastore’s name will be used in CP
  • Ensure that the OnApp CP server has admin access to the vCenter and all of the ESXi hosts