Returns a `list` of all the `ScaleIO_SDC` known to the cluster.  Updates every time - no caching.
        :return: a `list` of all the `ScaleIO_SDC` known to the cluster.
        :rtype: list

def sdc(self):
        """
        Returns a `list` of all the `ScaleIO_SDC` known to the cluster.  Updates every time - no caching.
        :return: a `list` of all the `ScaleIO_SDC` known to the cluster.
        :rtype: list
        """
        self.connection._check_login()
        response = self.connection._do_get("{}/{}".format(self.connection._api_url, "types/Sdc/instances")).json()       
        all_sdc = []
        for sdc in response:
            all_sdc.append(
                SIO_SDC.from_dict(sdc)
            )
        return all_sdc