装了新的CentOS8，才发现有很多原来使用的工具在新版本中已经被其他工具替代，今天把常规的系统时间同步问题解决一下，CentOS7及以下的都是采用NTP来解决，《linux中rc.local设置开机自启没有生效解决方案》。

找了一下方法，原来是使用了另一个工具替代了，记录一下先

[root@kiccleaf home]# yum install -y chrony

Installed:
  chrony-3.5-1.el8.x86_64                                                                                            timedatex-0.5-3.el8.x86_64                                                                                           

Complete!
安装好工具，先启动
[root@kiccleaf home]# systemctl start chronyd
设为系统自动启动
[root@kiccleaf home]# systemctl enable chronyd
编辑一下配置文件
[root@kiccleaf home]# vim /etc/chrony.conf

/etc/chrony.conf配置文件内容：

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#pool 2.centos.pool.ntp.org iburst （这一行注释掉，增加以下两行）
server ntp.aliyun.com iburst
server cn.ntp.org.cn iburst

重新加载配置
[root@kiccleaf home]# systemctl restart chronyd.service
[root@kiccleaf home]# chronyc sources -v
210 Number of sources = 2

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
 / .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^* 203.107.6.88                  2   6     7     2   -188us[+6871us] +/-   24ms
^- 61.177.189.190                3   6    17    19   +663us[ +663us] +/-   97ms

[root@kiccleaf home]# date
Sat Aug 29 16:26:08 CST 2020