'Returns an error if prerequisites aren\'t met.'

def check_for_setup_error(self):

    self.common.check_for_setup_error()
    if (len(self.gateway_iscsi_ip_addresses) == 0):
        msg = _('No    iSCSI    IPs    configured    on    SAN    gateway')
        raise exception.ViolinInvalidBackendConfig(reason=msg)
