CentOS8中默認已經不再支持ntpd軟件包，同時也無法通過官方軟件倉庫安裝， CentOS8上使用Chrony配置NTP服務器，用於同步時間。 它有兩個程序，chrony和chronyd， chronyd是守護進程 ，chrony是一個命令行界面程序，可以用來監控chronyd的性能，並修改各種操作參數。
安裝chrony
系統會默認安裝並啟動，如果系統不存在則需要安裝此工具庫。
倉庫中直接安裝
dnf -y install chrony
啟動守護進程
systemctl enable –now chronyd
時間同步配置
設置時區
聯網的情況下一般設置時區后會通過網絡同步時間
timedatectl set-timezone "Asia/Shanghai"
配置chrony.conf
修改配置加入aliyun pool網絡時間，也可以加入多個pool服務器
vim /etc/chrony.conf
# 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 pool ntp.aliyun.com 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. #allow 192.168.0.0/16 # Serve time even if not synchronized to a time source. #local stratum 10 # Specify file containing keys for NTP authentication. keyfile /etc/chrony.keys # Get TAI-UTC offset and leap seconds from the system tz database. leapsectz right/UTC # Specify directory for log files. logdir /var/log/chrony # Select which information is logged. #log measurements statistics tracking
重新加載配置
systemctl restart chronyd.service
時間同步
執行時間同步命令
chronyc sources -v
[root@k8smaster ~]# chronyc sources -v
210 Number of sources = 5
.-- 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
^- ntp5.flashdance.cx 2 6 377 6 +8255us[+8255us] +/- 139ms
^- 185.216.231.25 2 7 13 6 +10ms[ +10ms] +/- 98ms
^- 119.28.206.193 2 6 377 9 +1016us[+1001us] +/- 62ms
^* dns1.synet.edu.cn 2 6 377 8 -1423us[-1438us] +/- 9294us
^+ 203.107.6.88 2 6 377 7 +2107us[+2107us] +/- 17ms
驗證查看時間
查看當前系統時間
date