'Get the minimun mapping channel id and multi lun id mapping info.
# R model with mcs
map_chl = {
\'slot_a\': [\'0\', \'1\']
map_lun = [\'0\']
# G model with mcs
map_chl = {
\'slot_a\': [\'1\', \'2\']
map_lun = [\'0\']
:returns: minimun mapping channel id per slot and multi lun id'

def _get_mapping_info_with_mcs(self):

    map_chl = {'slot_a': []}
    min_lun_num = 0
    map_mcs_group = None
    for mcs in self.mcs_dict['slot_a']:
        if (len(self.mcs_dict['slot_a'][mcs]) > 1):
            if (min_lun_num < self._get_mcs_channel_lun_map_num(mcs)):
                min_lun_num = self._get_mcs_channel_lun_map_num(mcs)
                map_mcs_group = mcs
    if (map_mcs_group is None):
        msg = _('Raid    did    not    have    MCS    Channel.')
        LOG.error(msg)
        raise exception.VolumeDriverException(message=msg)
    map_chl['slot_a'] = self.mcs_dict['slot_a'][map_mcs_group]
    map_lun = self._get_mcs_channel_lun_map(map_chl['slot_a'])
    return (map_chl, map_lun, map_mcs_group)
