Port server moxi on node 'ns_1@10.3.121.97' exited with status 1.

I reboot one vms install couchbase server 2.0.2-746.
After the vm is up and couchbase server started, I saw error "Port server moxi on node 'ns_1@10.3.121.97' exited with status 1." in log page

Port server moxi on node 'ns_1@10.3.121.97' exited with status 1. Restarting. Messages: 2013-04-02 15:48:43: (cproxy_config.c.317) env: MOXI_SASL_PLAIN_USR (13)
2013-04-02 15:48:43: (cproxy_config.c.326) env: MOXI_SASL_PLAIN_PWD (8)
2013-04-02 15:48:45: (cproxy.c.330) ERROR: could not listen on port 11211. Please use -Z port_listen=PORT_NUM to specify a different port number. ns_port_server000 ns_1@10.3.121.97 15:48:43 - Tue Apr 2, 2013
Port server moxi on node 'ns_1@10.3.121.97' exited with status 1. Restarting. Messages: 2013-04-02 15:48:38: (cproxy_config.c.317) env: MOXI_SASL_PLAIN_USR (13)
2013-04-02 15:48:38: (cproxy_config.c.326) env: MOXI_SASL_PLAIN_PWD (8)
2013-04-02 15:48:40: (cproxy.c.330) ERROR: could not listen on port 11211. Please use -Z port_listen=PORT_NUM to specify a different port number. ns_port_server000 ns_1@10.3.121.97 15:48:38 - Tue Apr 2, 2013
Service moxi exited on node 'ns_1@10.3.121.97' in 0.01s
supervisor_cushion001 ns_1@10.3.121.97 15:48:33 - Tue Apr 2, 2013
Port server moxi on node 'ns_1@10.3.121.97' exited with status 1. Restarting. Messages: 2013-04-02 15:48:33: (cproxy_config.c.317) env: MOXI_SASL_PLAIN_USR (13)
2013-04-02 15:48:33: (cproxy_config.c.326) env: MOXI_SASL_PLAIN_PWD (8)
2013-04-02 15:48:35: (cproxy.c.330) ERROR: could not listen on port 11211. Please use -Z port_listen=PORT_NUM to specify a different port number. ns_port_server000 ns_1@10.3.121.97 15:48:33 - Tue Apr 2, 2013
Port server moxi on node 'ns_1@10.3.121.97' exited with status 1. Restarting. Messages: 2013-04-02 15:48:28: (cproxy_config.c.317) env: MOXI_SASL_PLAIN_USR (13)
2013-04-02 15:48:28: (cproxy_config.c.326) env: MOXI_SASL_PLAIN_PWD (8)
2013-04-02 15:48:30: (cproxy.c.330) ERROR: could not listen on port 11211. Please use -Z port_listen=PORT_NUM to specify a different port number. ns_port_server000 ns_1@10.3.121.97 15:48:28 - Tue Apr 2, 2013

I will attach collect info file soon