Depending on your security concerns, you can either have each vFiler unit register with the virus scanner or allow the vFiler units to use the host system's virus scanners.
If you have several vFiler units owned by separate departments, and you have security concerns, then you might want to have the virus scanner register with each vFiler unit. For more information, see the documentation for the virus-scanning software.
You can have the virus scanner register with only the physical system. In this way, only the system authenticates the virus scanner.