随笔

目录

1. ntp 校验

2. timedatectl 命令来进行时间同步

2.1 安装 Chrony 软件包

2.2 编辑Chrony的配置文件/etc/chrony.conf，选择你想要同步的NTP服务器

2.3 确认Chrony服务已经启动

2.4 命令查看系统时间与NTP服务器的同步情况

1. ntp 校验

<code>1. 确保你的系统上安装了NTP客户端软件

[root@bogon instanta]# ntpdate pool.ntp.ort

bash: ntpdate: command not found... # 没有安装 ntp

[root@bogon instanta]#

2. 安装 ntp

# yum install ntp

3. 使用ntpdate命令来进行网络时间校准

# sudo ntpdate pool.ntp.org

2. timedatectl 命令来进行时间同步

最新版本的CentOS 7中，NTP已被替换为Chrony作为时间同步服务。

2.1 安装 Chrony 软件包

如果你在执行ntpdate命令时遇到"command not found"的错误消息，这意味着 ntpdate 命令没有在你的系统上安装或找不到可执行文件。在某些较新的Linux发行版中，ntpdate 可能已被弃用或替代。

解决这个问题的一种方法是使用 timedatectl 命令来进行时间同步

1. 安装Chrony软件包

# yum intall chrony

[root@bogon instanta]# yum install chrony

Last metadata expiration check: 2:45:22 ago on Sat 11 May 2024 09:33:20 PM CST.

Package chrony-4.2-1.el8.x86_64 is already installed.

Dependencies resolved.

==============================================================================================================================================================================

Package Architecture Version Repository Size

==============================================================================================================================================================================

Upgrading:

chrony x86_64 4.5-1.el8 baseos 357 k

Transaction Summary

==============================================================================================================================================================================

Upgrade 1 Package

Total download size: 357 k

Is this ok [y/N]: y

Downloading Packages:

chrony-4.5-1.el8.x86_64.rpm 23 kB/s | 357 kB 00:15

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Total 23 kB/s | 357 kB 00:15

Running transaction check

Transaction check succeeded.

Running transaction test

Transaction test succeeded.

Running transaction

Preparing : 1/1

Running scriptlet: chrony-4.5-1.el8.x86_64 1/1

Running scriptlet: chrony-4.5-1.el8.x86_64 1/2

Upgrading : chrony-4.5-1.el8.x86_64 1/2

Running scriptlet: chrony-4.5-1.el8.x86_64 1/2

Running scriptlet: chrony-4.2-1.el8.x86_64 2/2

Cleanup : chrony-4.2-1.el8.x86_64 2/2

Running scriptlet: chrony-4.2-1.el8.x86_64 2/2

Verifying : chrony-4.5-1.el8.x86_64 1/2

Verifying : chrony-4.2-1.el8.x86_64 2/2

Upgraded:

chrony-4.5-1.el8.x86_64

Complete!

[root@bogon instanta]#

2.2 编辑Chrony的配置文件/etc/chrony.conf，选择你想要同步的NTP服务器

选择你想要同步的NTP服务器。你可以在配置文件中找到已列出的NTP服务器列表，使用你所偏好的NTP服务器。例如，你可以添加以下行来同步到CentOS提供的默认NTP服务器：

server 0.centos.pool.ntp.org iburst

server 1.centos.pool.ntp.org iburst

server 2.centos.pool.ntp.org iburst

[root@bogon instanta]# vi /etc/chrony.conf

server 0.centos.pool.ntp.org iburst

server 1.centos.pool.ntp.org iburst

server 2.centos.pool.ntp.org iburst

[root@bogon instanta]# tail -10 /etc/chrony.conf

# Specify directory for log files.

logdir /var/log/chrony

# Select which information is logged.

#log measurements statistics tracking

server 0.centos.pool.ntp.org iburst

server 1.centos.pool.ntp.org iburst

server 2.centos.pool.ntp.org iburst

[root@bogon instanta]#

2.3 保存并关闭配置文件后，重启Chrony服务以应用更改

# sudo systemctl restart chronyd

[root@bogon instanta]# systemctl restart chronyd

[root@bogon instanta]#

2.3 确认Chrony服务已经启动

确认Chrony服务已经启动，并且正在与NTP服务器进行时间同步。

如果chronyd服务正在运行，并且状态显示为"active (running)"，说明Chrony服务已配置并正常工作。

现在，你的系统应该在后台通过Chrony与NTP服务器自动进行时间同步

使用以下命令检查Chrony服务状态

# systemctl status chronyd

[root@bogon instanta]#

[root@bogon instanta]# systemctl status chronyd

● chronyd.service - NTP client/server

Loaded: loaded (/usr/lib/systemd/system/chronyd.service; disabled; vendor preset: enabled)

Active: active (running) since Sun 2024-05-12 00:28:37 CST; 8h left

Docs: man:chronyd(8)

man:chrony.conf(5)

Process: 20088 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)

Process: 20084 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 20086 (chronyd)

Tasks: 1 (limit: 821382)

Memory: 964.0K

CGroup: /system.slice/chronyd.service

└─20086 /usr/sbin/chronyd

May 12 00:28:36 bogon systemd[1]: Starting NTP client/server...

May 12 00:28:36 bogon chronyd[20086]: chronyd version 4.5 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +NTS +SECHASH +IPV6 +DEBUG)

May 12 00:28:36 bogon chronyd[20086]: Loaded 0 symmetric keys

May 12 00:28:36 bogon chronyd[20086]: Using right/UTC timezone to obtain leap second data

May 12 00:28:37 bogon systemd[1]: Started NTP client/server.

May 12 00:28:42 bogon chronyd[20086]: Selected source 202.112.31.197 (2.centos.pool.ntp.org)

May 12 00:28:42 bogon chronyd[20086]: System clock wrong by -29157.764766 seconds

May 11 16:22:44 bogon chronyd[20086]: System clock was stepped by -29157.764766 seconds

May 11 16:22:44 bogon chronyd[20086]: System clock TAI offset set to 37 seconds

[root@bogon instanta]#

2.4 命令查看系统时间与NTP服务器的同步情况

系统时间会逐渐校准到正确的时间。你可以使用以下命令查看系统时间与NTP服务器的同步情况：

# chronyc tracking

[root@bogon instanta]#

[root@bogon instanta]# chronyc tracking

Reference ID : CA701FC5 (dns2.synet.edu.cn)

Stratum : 2

Ref time (UTC) : Sat May 11 08:22:45 2024

System time : 0.000001325 seconds fast of NTP time

Last offset : +0.000001779 seconds

RMS offset : 0.000001779 seconds

Frequency : 13.598 ppm fast

Residual freq : +0.000 ppm

Skew : 157.455 ppm

Root delay : 0.012316211 seconds

Root dispersion : 0.005261188 seconds

Update interval : 2.0 seconds

Leap status : Normal

[root@bogon instanta]#

至此 CentOS7 已完成网络时间校准