ntpdate報錯the NTP socket is in use, exiting

客戶端使用ntpdate與NTP服務器進行時鐘同步時，報錯“the NTP socket is in use, exiting”，如下：
[root@h3 vdsm]# ntpdate 192.168.0.253
21 Feb 03:04:30 ntpdate[19759]: the NTP socket is in use, exiting

原因：ntp服務已運行
解決辦法：
[root@h3 vdsm]# /etc/init.d/ntpd stop
Shutting down ntpd:                                        [  OK  ]
[root@h3 vdsm]# ntpdate 192.168.0.253
21 Feb 03:06:55 ntpdate[19961]: step time server 192.168.0.253 offset 46.911562 sec