Linux-Chrony

Chrony

chrony CentOS 7 同步时间

情景

某LAN 内有 3 台机器，需要保持LAN内机器时间一致。

	A-机器IP: 192.168.137.100
	B-机器IP: 192.168.137.101
	C-机器IP: 192.168.137.102

分析

以 A-机器作为时间服务器，B-机器、C-机器 的时间与 A-机器 的时间同步即可。

操作

• 修改 A 机器 /etc/chrony.conf 文件

  添加：

    server 192.168.137.100 iburst # NTP 服务器
    allow 192.168/16 	# 服务端允许连接的客户端网段
    local stratum 10
  

  如:

     [root@192 ~]# cat /etc/chrony.conf 
     # Use public servers from the pool.ntp.org project.
     # Please consider joining the pool (http://www.pool.ntp.org/join.html).
     #server 0.centos.pool.ntp.org iburst
     #server 1.centos.pool.ntp.org iburst
     #server 2.centos.pool.ntp.org iburst
     #server 3.centos.pool.ntp.org iburst
     server 192.168.137.100 iburst
       
     # Ignore stratum in source selection.
     stratumweight 0
       
     # Record the rate at which the system clock gains/losses time.
     driftfile /var/lib/chrony/drift
       
     # Enable kernel RTC synchronization.
     rtcsync
       
     # In first three updates step the system clock instead of slew
     # if the adjustment is larger than 10 seconds.
     makestep 10 3
       
     # Allow NTP client access from local network.
     allow 192.168/16
       
     # Listen for commands only on localhost.
     bindcmdaddress 127.0.0.1
     bindcmdaddress ::1
       
     # Serve time even if not synchronized to any NTP server.
     local stratum 10
       
     keyfile /etc/chrony.keys
       
     # Specify the key used as password for chronyc.
     commandkey 1
       
     # Generate command key if missing.
     generatecommandkey
       
     # Disable logging of client accesses.
     noclientlog
       
     # Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
     logchange 0.5
       
     logdir /var/log/chrony
     #log measurements statistics tracking
     [root@192 ~]# 
  
  	
  

• 修改 B、C 机器 /etc/chrony.conf 文件

  添加：

    server 192.168.137.100 iburst # NTP 服务器
  
    local stratum 10
  

  如:

    [root@192 ~]# cat /etc/chrony.conf 
    # Use public servers from the pool.ntp.org project.
    # Please consider joining the pool (http://www.pool.ntp.org/join.html).
    #server 0.centos.pool.ntp.org iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst
    server 192.168.137.100 iburst
      
    # Ignore stratum in source selection.
    stratumweight 0
      
    # Record the rate at which the system clock gains/losses time.
    driftfile /var/lib/chrony/drift
      
    # Enable kernel RTC synchronization.
    rtcsync
      
    # In first three updates step the system clock instead of slew
    # if the adjustment is larger than 10 seconds.
    makestep 10 3
      
    # Allow NTP client access from local network.
    #allow 192.168/16
      
    # Listen for commands only on localhost.
    bindcmdaddress 127.0.0.1
    bindcmdaddress ::1
      
    # Serve time even if not synchronized to any NTP server.
    local stratum 10
      
    keyfile /etc/chrony.keys
      
    # Specify the key used as password for chronyc.
    commandkey 1
      
    # Generate command key if missing.
    generatecommandkey
      
    # Disable logging of client accesses.
    noclientlog
      
    # Send a message to syslog if a clock adjustment is larger than 0.5 seconds.
    logchange 0.5
      
    logdir /var/log/chrony
    #log measurements statistics tracking
    [root@192 ~]# 
      
      	
  

• 重启 chrond 服务

  重启A、B、C机器的chronyd 服务

    [root@192 ~]# systemctl restart chronyd.service
    [root@192 ~]# 
  

• 同步时间

  在 B、C 机器执行 chronyc -a makestep 同步时间即可。

注意事项

1.chronyd 与 ntpd 服务是两个相同功能的东西，不能同时运行。
也就是说，chronyd 的 status 是 running 时，ntpd 的 status 应是dead。

2.同步失败，注意防火墙。

相关命令

	systemctl enable chronyd.service  # chronyd 服务开机启动
	systemctl status chronyd.service  # chronyd 服务状态

	timedatectl set-timezone Asia/Shanghai  #设置时区Asia/Shanghai