[root@ntp-server ~]# timedatectl
Local time: Tue 2018-08-21 14:02:35 CST
Universal time: Tue 2018-08-21 06:02:35 UTC
RTC time: Tue 2018-08-21 06:02:33
Time zone: Asia/Shanghai (CST, +0800)
NTP enabled: n/a
NTP synchronized: no
RTC in local TZ: no
DST active: n/a
[root@ntp-server ~]# timedatectl
list-timezones set-ntp set-timezone
set-local-rtc set-time status
[root@ntp-server ~]# timedatectl list-timezones | grep -i shanghai
Asia/Shanghai
//关闭NTP
[root@ntp-server ~]# timedatectl set-ntp false
[root@ntp-server ~]# timedatectl
Local time: Tue 2018-08-21 14:15:36 CST
Universal time: Tue 2018-08-21 06:15:36 UTC
RTC time: Tue 2018-08-21 06:15:36
Time zone: Asia/Shanghai (CST, +0800)
NTP enabled: no
NTP synchronized: yes
RTC in local TZ: no
DST active: n/a
//启用NTP
[root@ntp-server ~]# timedatectl set-ntp true
[root@ntp-server ~]# timedatectl
Local time: Tue 2018-08-21 14:16:02 CST
Universal time: Tue 2018-08-21 06:16:02 UTC
RTC time: Tue 2018-08-21 06:16:02
Time zone: Asia/Shanghai (CST, +0800)
NTP enabled: yes
NTP synchronized: no
RTC in local TZ: no
DST active: n/a
//查看一下ntpdate由哪个包提供的
[root@ntp-server ~]# yum provides ntpdate
Loaded plugins: product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
ntpdate-4.2.6p5-25.el7_3.2.x86_64 : Utility to set the date and time via NTP
Repo : dvd
//如果没有请安装ntpdate
[root@ntp-server ~]# yum install ntpdate.x86_64
Loaded plugins: product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
Resolving Dependencies
--> Running transaction check
---> Package ntpdate.x86_64 0:4.2.6p5-25.el7_3.2 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==========================================================================================
Package Arch Version Repository Size
==========================================================================================
Installing:
ntpdate x86_64 4.2.6p5-25.el7_3.2 dvd 86 k
Transaction Summary
==========================================================================================
Install 1 Package
Total download size: 86 k
Installed size: 121 k
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : ntpdate-4.2.6p5-25.el7_3.2.x86_64 1/1
Verifying : ntpdate-4.2.6p5-25.el7_3.2.x86_64 1/1
Installed:
ntpdate.x86_64 0:4.2.6p5-25.el7_3.2
Complete!
2.配置时间同步服务器
[root@ntp-server ~]# vim /etc/chrony.conf
server ntp1.aliyun.com iburst
server ntp2.aliyun.com iburst
server ntp3.aliyun.com iburst
server ntp4.aliyun.com iburst
server ntp5.aliyun.com iburst
server ntp6.aliyun.com iburst
server ntp7.aliyun.com iburst
allow 172.16.10.0/24
//验证服务端是否能同步时间
[root@ntp-server ~]# chronyc sources -v
210 Number of sources = 1
.-- 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
===============================================================================
^* 120.25.115.20 2 6 17 22 -117us[ -948us] +/- 24ms
//看一下服务器时间
[root@ntp-server ~]# date
Tue Aug 21 15:31:29 CST 2018
//看一下客户端时间 时间不对需要同步
[root@ntp-client ~]# date
Fri Aug 20 14:10:28 CST 2010