Centos 7/8 Chronyd时间同步

Chronyd

chronyd是一个同步系统时钟的守护进程。

从Centos7开始默认安装时钟同步服务chronyd，而不是ntpd。

# dnf -y install chronyd
# eccho 'server ntp1.aliyun.com iburst' >> /etc/chrony.conf
# systemctl enable chronyd.service && systemctl start chronyd.service

Chronyc

chronyc is a command-line interface program which can be used to monitor chronyd’s performance and to change various operating parameters whilst it is running.

# chronyc sources -v
  .-- 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               
===============================================================================
^* classroom.example.com         8  10   377  1000   +130us[ +147us] +/-  819us

Timedatectl

Query or change system time and date settings.

set-timezone

　　设置时区，也可以手动执行localtime软连接

　　# timedatectl set-timezone Asia/Shanghai
　　# ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

set-ntp BOOL

　　和chrony配置的ntp server进行时间同步

set-time TIME

　　手动设置日期时间