一，chrony服务同步时间

1，实验一:第一台机器从阿里云同步时间 第二台机器从第一台机器同步时间

下载所需要的yum源，并启动服务

yum -y install chrony
systemctl enable chronyd
systemctl start chronyd

我这里用的是麒麟服务器 V0 SP3自带有所以不用再次下载

[root@server ~]# nkvers 
############## Kylin Linux Version #################
Release:
Kylin Linux Advanced Server release V10 (Lance)

Kernel:
4.19.90-52.31.v2207.ky10.x86_64

Build:
Kylin Linux Advanced Server
release V10 (SP3) /(Lance)-x86_64-Build23/20230324
#################################################

#查看chrony服务状态

[root@server ~]# 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 2023-12-28 14:52:37 CST; 8min ago
     Docs: man:chronyd(8)
           man:chrony.conf(5)
  Process: 779 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
  Process: 796 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)
 Main PID: 784 (chronyd)
    Tasks: 1
   Memory: 948.0K
   CGroup: /system.slice/chronyd.service
           └─784 /usr/sbin/chronyd

Chrony的配置文件是/etc/chrony.conf，进入第一台机子的配置文件，根据你具体的所需参数修改如下：

#pool pool.ntp.org iburst
#server ntp.ntsc.ac.cn iburst
##指定阿里云的时间服务器为服务器时间,生产环境中建议大家指定多个事件服务器哟,起到对时间服务器备份的效果
server ntp1.aliyun.com iburst
#server cn.pool.ntp.org iburst

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Allow the system clock to be stepped in the first three updates
# if its offset is larger than 1 second.
makestep 1.0 3

# Enable kernel synchronization of the real-time clock (RTC).
rtcsync

# Enable hardware timestamping on all interfaces that support it.
#hwtimestamp *

# Increase the minimum number of selectable sources required to adjust
# the system clock.
#minsources 2

# Allow NTP client access from local network.
#指定允许的客户端网段来当前时间服务器节点同步时间,我们可以使用deny all拒绝所有客户端。
allow 192.0.0.0/8

# Serve time even if not synchronized to a time source.
local stratum 10        #当网络时间不可以时使用本地时间
    

设置开机启动，重启服务

[root@server ~]# systemctl enable chronyd
[root@server ~]# systemctl restart chronyd

使用chronyc sources查看时间同步状态

[root@server ~]# chronyc sources
210 Number of sources = 2
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- 114.118.7.161                 1   7    26   148  +2722us[+3262us] +/-   50ms
^* 120.25.115.20                 2   7   353    82   +885us[+1472us] +/-   40ms
[root@server ~]# chronyc sources
210 Number of sources = 2
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^- 114.118.7.161                 1   7    26   154  +2722us[+3262us] +/-   50ms
^* 120.25.115.20                 2   7   353    86   +885us[+1472us] +/-   40ms

　^*表示chronyd当前同步到的时钟源

2，客户端配置

修改hosts文件做映射

[root@client ~]# tail /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.200.108 server

客户端配置chrony

[root@client ~]# egrep -v "#|^$" /etc/chrony.conf 
server server  iburst          #只需要修改此行即可
driftfile /var/lib/chrony/drift
makestep 1.0 3
rtcsync
logdir /var/log/chrony
    

重启服务

[root@client ~]# systemctl restart chronyd
[root@client ~]# systemctl enable chronyd