####时间同步####
1.服务端
yum install chrony -y ##安装服务
vim /etc/chrony.conf ##主配置文件
21 # Allow NTP client access from local network.
22 allow 172.25.0.0/24 ##允许谁去同步我的时间
27 # Serve time even if not synchronized to any NTP server.
28 local stratum 10 ##不去同步任何人的时间，时间同步服务器级别
systemctl restart chronyd
systemctl stop firewalld
2.客户端
vim /etc/chrony.conf
3 server 0.rhel.pool.ntp.orgiburst
4 server 1.rhel.pool.ntp.orgiburst====> server ntpserverip iburst
5 server 2.rhel.pool.ntp.org iburst====>
6 server 3.rhel.pool.ntp.orgiburst
systemctl restart chronyd
测试：
[root@localhost ~]# chronyc sources -v
210 Number of sources = 1
.-- Source mode '^' = server, '=' = peer, '#' = localclock.
/ .- Source state '*' = current synced,'+' = combined , '-' = not combined,
| / '?' = unreachable, 'x' = time maybe in error, '~' = time too variable.
|| .- xxxx [ yyyy ] +/- zzzz
|| / xxxx = adjusted offset,
|| Log2(Polling interval) -. | yyyy = measured offset,
|| \ | zzzz = estimated error.
|| | |
MS Name/IP address Stratum PollReach LastRx Last sample
===============================================================================
^* 172.25.0.11 10 6 377 41 +170us[ +201us] +/- 191us
####5.timedatectl命令####
timedatectl status ##显示当前时间信息
set-time ##设定当前时间
set-timezone ##设定当前时区
set-local-rtc 0|1 ##设定是否使用utc时间
