一、使用NTP服务时间同步
1.安装ntp
[root@node ~]# yum -y install ntp
2.启动ntp服务
[root@node ~]# systemctl start ntpd
[root@node ~]# systemctl enable ntpd
Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.
3.查看ntp服务
[root@node ~]# systemctl status ntpd
● ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled; vendor preset: disabled)
Active: active (running) since Thu 2022-08-04 08:00:47 CST; 7h left
Main PID: 20746 (ntpd)
Tasks: 1
Memory: 768.0K
CGroup: /system.slice/ntpd.service
└─20746 /usr/sbin/ntpd -u ntp:ntp -g
Aug 04 08:00:47 node ntpd[20746]: Listen normally on 6 lo ::1 UDP 123
Aug 04 08:00:47 node ntpd[20746]: Listen normally on 7 ens33 fe80::8a83:7297:7cb8:9934 UDP 123
Aug 04 08:00:47 node ntpd[20746]: Listening on routing socket on fd #24 for interface updates
Aug 04 08:00:47 node systemd[1]: Started Network Time Service.
Aug 04 08:00:47 node ntpd[20746]: 0.0.0.0 c016 06 restart
Aug 04 08:00:47 node ntpd[20746]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM
Aug 04 08:00:47 node ntpd[20746]: 0.0.0.0 c011 01 freq_not_set
Aug 04 08:00:56 node ntpd[20746]: 0.0.0.0 c61c 0c clock_step -28798.353463 s
Aug 04 00:00:57 node ntpd[20746]: 0.0.0.0 c614 04 freq_mode
Aug 04 00:00:58 node ntpd[20746]: 0.0.0.0 c618 08 no_sys_peer
4.修改ntp.conf文件
[root@node ~]# vim /etc/ntp.conf
[root@node ~]# grep server /etc/ntp.conf
# Use public servers from the pool.ntp.org project.
#server 0.centos.pool.ntp.org iburst
server ntp.aliyun.com iburst
#broadcast 192.168.1.255 autokey # broadcast server
#broadcast 224.0.1.1 autokey # multicast server
#manycastserver 239.255.254.254 # manycast server
5.重启服务
[root@node ~]# systemctl restart ntpd
6.检查同步状态
[root@node ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
203.107.6.88 100.107.25.114 2 u 2 64 1 30.975 149.499 0.393
二、使用ntpdate同步
1.使用ntpd命令同步
[root@node ~]# ntpdate ntp.aliyun.com
4 Aug 00:07:17 ntpdate[20924]: adjust time server 203.107.6.88 offset -0.001543 sec
2.查看时间
[root@node ~]# date
Thu Aug 4 00:07:46 CST 2022
三、处理ntpdate同步失败报错处理方法
1.报错信息
cna02:~ # ntpdate ntp1.aliyun.com
4 Aug 07:23:41 ntpdate[18694]: the NTP socket is in use, exiting
2.处理方法
cna02:~ # service ntpd stop
Redirecting to /bin/systemctl stop ntpd.service
3.重新同步
cna02:~ # ntpdate ntp1.aliyun.com
3 Aug 23:22:36 ntpdate[28980]: step time server 120.25.115.20 offset -28911.609110 sec
4.查看时间是否正确
cna02:~ # date
Wed Aug 3 23:22:41 CST 2022
四、使用chrony服务时间同步
1.安装chrony
[root@node ~]# yum -y install chrony
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirrors.bfsu.edu.cn
* extras: mirrors.bfsu.edu.cn
* updates: mirrors.bfsu.edu.cn
Resolving Dependencies
--> Running transaction check
---> Package chrony.x86_64 0:3.2-2.el7 will be updated
---> Package chrony.x86_64 0:3.4-1.el7 will be an update
--> Finished Dependency Resolution
Dependencies Resolved
===============================================================================================================================================================================
Package Arch Version Repository Size
===============================================================================================================================================================================
Updating:
chrony x86_64 3.4-1.el7 base 251 k
Transaction Summary
===============================================================================================================================================================================
Upgrade 1 Package
Total download size: 251 k
Downloading packages:
No Presto metadata available for base
chrony-3.4-1.el7.x86_64.rpm | 251 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Updating : chrony-3.4-1.el7.x86_64 1/2
Cleanup : chrony-3.2-2.el7.x86_64 2/2
Verifying : chrony-3.4-1.el7.x86_64 1/2
Verifying : chrony-3.2-2.el7.x86_64 2/2
Updated:
chrony.x86_64 0:3.4-1.el7
Complete!
2.启动chrony服务
[root@node ~]# systemctl enable --now chronyd
Created symlink from /etc/systemd/system/multi-user.target.wants/chronyd.service to /usr/lib/systemd/system/chronyd.service.
3.查看chrony状态
[root@node ~]# systemctl status chronyd
● chronyd.service - NTP client/server
Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2022-08-04 00:12:27 CST; 29s ago
Docs: man:chronyd(8)
man:chrony.conf(5)
Process: 21136 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)
Process: 21132 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 21134 (chronyd)
Tasks: 1
Memory: 364.0K
CGroup: /system.slice/chronyd.service
└─21134 /usr/sbin/chronyd
Aug 04 00:12:27 node systemd[1]: Starting NTP client/server...
Aug 04 00:12:27 node chronyd[21134]: chronyd version 3.4 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +SECHASH +IPV6 +DEBUG)
Aug 04 00:12:27 node systemd[1]: Started NTP client/server.
Aug 04 00:12:35 node chronyd[21134]: Selected source 193.182.111.141
Aug 04 00:12:35 node chronyd[21134]: Source 78.46.102.180 replaced with 94.237.64.20
4.修改配置文件
[root@node ~]# grep server /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
server ntp1.aliyun.com iburst
5.重启服务
[root@node ~]# systemctl restart chronyd
6.检查时间同步状态
[root@node ~]# chronyc sources
210 Number of sources = 1
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* 120.25.115.20 2 6 71 26 +751us[+1549us] +/- 19ms
五、手动修改时间
1.修改时间方法1
[root@node ~]# date -s "2012-05-23 01:01:01"
Wed May 23 01:01:01 CST 2012
[root@node ~]# date
Wed May 23 01:01:05 CST 2012
2.修改时间方法2
修改时间顺序为月日时分年.秒
```cpp
[root@tianyi ~]# date 090621282021.28
Mon Sep 6 21:28:28 CST 2021
## 3.硬件时间向系统时间同步
```cpp
[root@node ~]# hwclock -w
4.按格式输出时间
[root@node ~]# date "+%Y-%m-%d %H:%M:%S"
2012-05-23 01:04:10
5.设置时区
[root@tianyi backups]# timedatectl list-timezones |grep Shanghai
Asia/Shanghai
[root@tianyi backups]# timedatectl set-timezone Asia/Shanghai
