The export and import of appliances in OVF and OVA format have been improved, as follows:
Exporting: You can select additional options that affect the size and content of the file archive. For example, you can include ISO image files in the exported archive file.
Options enable you to include and exclude network card MAC addresses on export.
Importing: You can select additional options for the imported appliance. For example, specify the base directory to use for storing VMs and the MAC address policy on import.
A new option enables the import of hard disk images in VDI format, rather than the default VMDK format.
By default, VM groups are preserved on import. You can use a new option to override this default behavior.
See Importing and Exporting Virtual Machines for more details.