'Find Dell SC QOS Node entry for replication.
:param qosnode: Name of qosnode.
:param ssn: SSN to search on.
:return: scqos node object.'

def _find_qos(self, qosnode, ssn=(-1)):

    ssn = self._vet_ssn(ssn)
    pf = self._get_payload_filter()
    pf.append('scSerialNumber', ssn)
    pf.append('name', qosnode)
    r = self.client.post('StorageCenter/ScReplicationQosNode/GetList', pf.payload)
    if self._check_result(r):
        nodes = self._get_json(r)
        if (len(nodes) > 0):
            return nodes[0]
        else:
            payload = {}
            payload['LinkSpeed'] = '1    Gbps'
            payload['Name'] = qosnode
            payload['StorageCenter'] = ssn
            payload['BandwidthLimited'] = False
            r = self.client.post('StorageCenter/ScReplicationQosNode', payload, True)
            if self._check_result(r):
                return self._get_json(r)
    LOG.error('Unable    to    find    or    create    QoS    Node    named    %s', qosnode)
    raise exception.VolumeBackendAPIException(data=_('Failed    to    find    QoSnode'))
