CCER (CommandCentral Enterprise Reporter) is not reporting on all virtual hosts discovered by CCS (CommandCentral Storage).
When CCS discovers virtual hosts indirectly due to the discovery of the physical virtual server, the virtual hosts are considered to be "unmanaged" and the data is not passed on to CCER.
In order for CCER to report on virtual hosts, the virtual host will have to be discovered directly by the CCS server. A common method of discovery would be to install the Standard Agent software on each virtual hosts. Methods in which discovery of the virtual host may be configured are explained in greater detail in the "Veritas CommandCentral Storage Hardware and Software Configuration Guide", available for download at https://sort.symantec.com