Returns the size of the occupied space on the hard disk.
PRL_RESULT PrlVmDevHd_GetSizeOnDisk( PRL_HANDLE hVmDev, PRL_UINT32_PTR pnOnDiskSize );
PrlApiVm.h
PRL_RESULT. Possible values:
PRL_ERR_INVALID_ARG - invalid handle or null pointer was passed.
PRL_ERR_SUCCESS - function completed successfully.