以CentOS7 做时间服务器，其他服务器（Centos 6、RHEL7）同步该服务器时间

RHEL 7、CentOS 7 默认的网络时间协议 为Chrony

本教程时间服务器服务端主机名：CentOS7-Node3    IP：192.168.231.130

                           客户端1主机名：RHEL7-Node1

                           客户端2主机名：CentOS6-Node2

服务端：

先查询下chrony服务状态

[root@CentOS7-Node3 ~]# systemctl status chronyd
Unit chronyd.service could not be found.
 

如果查询没有该服务，可yum安装

[root@CentOS7-Node3 ~]# yum install -y chrony

启动chrony服务  

[root@CentOS7-Node3 ~]# systemctl start chronyd
 

查询状态

[root@CentOS7-Node3 ~]# systemctl status chronyd
● chronyd.service - NTP client/server
   Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled) Active: active (running) since Thu 2018-06-07 10:20:28 CST; 2s ago Docs: man:chronyd(8) man:chrony.conf(5) Process: 6031 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS) Process: 6027 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS) Main PID: 6029 (chronyd) CGroup: /system.slice/chronyd.service └─6029 /usr/sbin/chronyd Jun 07 10:20:28 CentOS7-Node3 systemd[1]: Starting NTP client/server... Jun 07 10:20:28 CentOS7-Node3 chronyd[6029]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +...DEBUG) Jun 07 10:20:28 CentOS7-Node3 chronyd[6029]: Initial frequency -29.914 ppm Jun 07 10:20:28 CentOS7-Node3 systemd[1]: Started NTP client/server. Jun 07 10:20:33 CentOS7-Node3 chronyd[6029]: Selected source 37.218.240.198 Jun 07 10:20:33 CentOS7-Node3 chronyd[6029]: System clock wrong by -3.020089 seconds, adjustment started Jun 07 10:20:30 CentOS7-Node3 chronyd[6029]: System clock was stepped by -3.020089 seconds Hint: Some lines were ellipsized, use -l to show in full.
 

作为时间服务器做如下配置：

 [root@CentOS7-Node3 ~]# vim /etc/chrony.conf
25 # Allow NTP client access from local network.
26 allow 192.168.231.0/24
27 
28 # Serve time even if not synchronized to a time source. 29 local stratum 10
 

三台服务器时间，CentOS7-Node3为正常时间

图片.png

客户端配置：

客户端1：

将 server 0.rhel.pool.ntp.org iburst ---server 3.rhel.pool.ntp.org iburst 删除或注释

新增\修改配置：

server 192.168.231.130 iburt

allow 192.168.231.0/24

[root@RHEL7-Node1 ~]# vim /etc/chrony.conf
  1 # Use public servers from the pool.ntp.org project.  
  2 # Please consider joining the pool (http://www.pool.ntp.org/join.html). 3 #server 0.rhel.pool.ntp.org iburst 4 #server 1.rhel.pool.ntp.org iburst 5 #server 2.rhel.pool.ntp.org iburst 6 #server 3.rhel.pool.ntp.org iburst 7 server 192.168.231.130 iburst 8 # Ignore stratum in source selection. 9 stratumweight 0 10 11 # Record the rate at which the system clock gains/losses time. 12 driftfile /var/lib/chrony/drift 13 14 # Enable kernel RTC synchronization. 15 rtcsync 16 17 # In first three updates step the system clock instead of slew 18 # if the adjustment is larger than 10 seconds. 19 makestep 10 3 20 21 # Allow NTP client access from local network. 22 allow 192.168.231.0/24
 

修改完成后，保存，重启chrony服务即可生效

[root@RHEL7-Node1 ~]# systemctl restart chronyd

客户端2 CentOS6-Node2

CentOS 6 为NTP

执行 ntpdate 192.168.231.130

[root@CentOS6-Node2 ~]# ntpdate 192.168.231.130
 7 Jun 16:59:34 ntpdate[1563]: the NTP socket is in use, exiting
 

若出现上述错误，将ntp服务停止，再执行ntpdate 192.168.231.130

[root@CentOS6-Node2 ~]# service ntpd stop
Shutting down ntpd:                                        [  OK  ] [root@CentOS6-Node2 ~]# ntpdate 192.168.231.130 7 Jun 17:00:19 ntpdate[1578]: step time server 192.168.231.130 offset -13589998.9 54539 sec[root@CentOS6-Node2 ~]# service ntpd status ntpd is stopped [root@CentOS6-Node2 ~]# date Thu Jun 7 17:00:37 CST 2018
 

随后在计划任务中添加时间同步

[root@CentOS6-Node2 ~]# crontab -e
0-59/10 * * * * /usr/sbin/ntpdate 192.168.231.130
 

10分钟同步一次

现在查看下三台服务器时间是一致的了

图片.png