RedHat Linux NTP实施步骤
1、 查看本系统与NTP服务器的时间偏差
ntpdate -d 192.168.142.114
[root@zabbix-proxy ~]# ntpdate -d 192.168.142.114 24 Aug 17:26:45 ntpdate[3355]: ntpdate 4.2.6p5@1.2349-o Fri Apr 13 12:52:28 UTC 2018 (1) Looking for host 192.168.142.114 and service ntp host found : 192.168.142.114 transmit(192.168.142.114) receive(192.168.142.114) transmit(192.168.142.114) receive(192.168.142.114) transmit(192.168.142.114) receive(192.168.142.114) transmit(192.168.142.114) receive(192.168.142.114) server 192.168.142.114, port 123 stratum 1, precision -18, leap 00, trust 000 refid [MRS], delay 0.02600, dispersion 0.00003 transmitted 4, in filter 4 reference time: df2a4dd8.09606edb Fri, Aug 24 2018 17:26:48.036 originate timestamp: df2a4ddb.fbbb6da2 Fri, Aug 24 2018 17:26:51.983 transmit timestamp: df2a4ddb.fb8df6df Fri, Aug 24 2018 17:26:51.982 filter delay: 0.02602 0.02603 0.02600 0.02614 0.00000 0.00000 0.00000 0.00000 filter offset: -0.00005 -0.00002 0.000006 0.000037 0.000000 0.000000 0.000000 0.000000 delay 0.02600, dispersion 0.00003 offset 0.000006 24 Aug 17:26:51 ntpdate[3355]: adjust time server 192.168.142.114 offset 0.000006 sec
单位：秒
2、查看本系统之前是否配置过定时时间同步操作
crontab -l
若有，应删除 crontab -e
3、查看本系统时区是否正确
date
若不正确，则应停应用，调整时区,可以参考tzselect
4、查看本系统之前是否配置过ntp服务命令
service ntpd status
若有过配置，应关闭NTP服务
service ntpd stop
关闭NTP服务
5、确认NTP服务是否已经停止
ntpq -p
6、编辑文件/etc/ntp.conf
注释broadcastclient
#broadcastclient
需添加内容
server 192.168.150.142 minpoll 4 maxpoll 4 prefer ##maxpoll 4：2^4(16s)同步一次 server 192.168.150.143 minpoll 4 maxpoll 4 tinker step 0 ##如果使用缓慢调整应添加参数 driftfile /etc/ntp.drift ##默认系统自带，无需自己添加*/ tracefile /etc/ntp.trace
7、设置NTP服务开机自启动
chkconfig ntpd on
9、重启NTP服务
service ntpd restart
10、查看NTP运行状态
ntpq -p
显示内容类似如下
remote refid st t when poll reach delay offset jitter ============================================================================== 192.168.142.114 .MRS. 1 u 8 16 1 0.403 0.037 0.000 192.168.142.224 .INIT. 16 u - 16 0 0.000 0.000 0.000
补充：直接对时命令
ntpdate 192.168.142.114