（7）centos7 同步服务器时间

r囧r小猫 2022-12-27 12:55 240阅读 0赞

**一、服务器配置**

1、查看服务器、客户端操作系统版本

[root@hadoop101 ~]# cat /etc/redhat-release
    CentOS Linux release 7.6.1810 (Core)

2、查看服务器是否安装ntp，系统默认安装ntpdate；

[root@hadoop101 ~]# rpm -qa | grep ntp
    fontpackages-filesystem-1.44-8.el7.noarch
    ntpdate-4.2.6p5-28.el7.centos.x86_64
    python-ntplib-0.3.2-1.el7.noarch
    ntp-4.2.6p5-28.el7.centos.x86_64

3、安装ntp ntpdate，其中ntpdate默认安装，可以只安装ntp；

yum install ntp ntpdate -y

4、查看是否已安装完成，与第2步对比

[root@hadoop101 mysql-libs]# rpm -qa | grep ntp
    fontpackages-filesystem-1.44-8.el7.noarch
    ntpdate-4.2.6p5-28.el7.centos.x86_64
    ntp-4.2.6p5-28.el7.centos.x86_64
    python-ntplib-0.3.2-1.el7.noarch

5、查看ntp服务器状态，两条命令效果一样

[root@hadoop101 ~]# systemctl status ntpd
    ● ntpd.service - Network Time Service
    Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
    Active: inactive (dead)

或

[root@hadoop101 ~]# service ntpd status
    Redirecting to /bin/systemctl status ntpd.service
    ● ntpd.service - Network Time Service
    Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
    Active: inactive (dead)

6、修改配置文件，使该NTP服务器在不联网的情况下，使用本服务器的时间作为同步时间

vim /etc/ntp.conf

把如下四行代码注释掉

#server 0.centos.pool.ntp.org iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst

在下面再添加两行

server 127.127.1.0 
    fudge  127.127.1.0 stratum 0

配置后：

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

[root@hadoop101 ~]# vim /etc/ntp.conf
    # For more information about this file, see the man pages
    # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).
    
    driftfile /var/lib/ntp/drift
    
    # Permit time synchronization with our time source, but do not
    # permit the source to query or modify the service on this system.
    restrict default nomodify notrap nopeer noquery
    
    # Permit all access over the loopback interface.  This could
    # be tightened as well, but to do so would effect some of
    # the administrative functions.
    restrict 127.0.0.1
    restrict ::1
    
    # Hosts on local network are less restricted.
    #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
    
    # Use public servers from the pool.ntp.org project.
    # Please consider joining the pool (http://www.pool.ntp.org/join.html).
    #server 0.centos.pool.ntp.org iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst
    server 127.127.1.0
    fudge  127.127.1.0 stratum 0
    
    #broadcast 192.168.1.255 autokey        # broadcast server
    #broadcastclient                        # broadcast client
    #broadcast 224.0.1.1 autokey            # multicast server
    #multicastclient 224.0.1.1              # multicast client
    #manycastserver 239.255.254.254         # manycast server
    #manycastclient 239.255.254.254 autokey # manycast client
    
    # Enable public key cryptography.
    #crypto
    
    includefile /etc/ntp/crypto/pw
    
    # Key file containing the keys and key identifiers used when operating
    # with symmetric key cryptography.
    keys /etc/ntp/keys
    
    # Specify the key identifiers which are trusted.
    #trustedkey 4 8 42
    
    # Specify the key identifier to use with the ntpdc utility.
    #requestkey 8
    
    # Specify the key identifier to use with the ntpq utility.
    #controlkey 8
    
    # Enable writing of statistics records.

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

7、启动ntp服务

systemctl start ntpd

或

service ntpd start

8、再次查看服务器状态是否配置成功

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

[root@hadoop101 mysql-libs]# systemctl status ntpd
    ● ntpd.service - Network Time Service
       Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
       Active: active (running) since Fri 2019-08-16 18:33:01 CST; 13s ago
      Process: 8792 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
     Main PID: 8794 (ntpd)
        Tasks: 1
       CGroup: /system.slice/ntpd.service
               └─8794 /usr/sbin/ntpd -u ntp:ntp -g
    
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: Listen normally on 3 ...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: Listen normally on 4 ...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: Listen normally on 5 ...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: Listen normally on 6 ...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: Listening on routing ...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: 0.0.0.0 c016 06 restart
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: 0.0.0.0 c012 02 freq_...
    Aug 16 18:33:01 hadoop101.com ntpd[8794]: 0.0.0.0 c011 01 freq_...
    Aug 16 18:33:01 hadoop101.com systemd[1]: Started Network Time ...
    Aug 16 18:33:02 hadoop101.com ntpd[8794]: 0.0.0.0 c514 04 freq_...
    Hint: Some lines were ellipsized, use -l to show in full.

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

或

[root@hadoop101 ~]# service ntpd status

9、查看是否同步

[root@hadoop101 ~]# ntpq -p
    remote refid st t when poll reach delay offset jitter
    ==============================================================================
    *LOCAL(0) .LOCL. 5 l 20 64 7 0.000 0.000 0.000

10、设置开机启动

[root@hadoop101 ~]# systemctl enable ntpd
    Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.

11、设置防火墙，打开udp123端口（如果防火墙关了就不用设置了）

[root@hadoop101 ~]# firewall-cmd --permanent --add-port=123/udp
    success
    [root@hadoop101 ~]# firewall-cmd --reload
    success

12、查看防火墙已打开端口

iptables -L -n

**二、客户端配置（其他节点）**

前5步与服务器一致

6、修改配置文件，将刚刚搭建好的NTP服务器作为客户端上游时间服务器

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

vim /etc/ntp.conf
    #注释掉其他上游时间服务器
    #server 0.centos.pool.ntp.org iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst
    #配置上游时间服务器为本地的ntpd Server服务器
    server hadoop101.com
    fudge hadoop101.com stratum 0
    
    #配置允许上游时间服务器主动修改本机的时间
    restrict hadoop101.com nomodify notrap noquery

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

配置后：

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

[root@hadoop103 ~]# vi /etc/ntp.conf 
    # For more information about this file, see the man pages
    # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).
    
    driftfile /var/lib/ntp/drift
    
    # Permit time synchronization with our time source, but do not
    # permit the source to query or modify the service on this system.
    #restrict default nomodify notrap nopeer noquery
    
    # Permit all access over the loopback interface.  This could
    # be tightened as well, but to do so would effect some of
    # the administrative functions.
    #restrict 127.0.0.1
    #restrict ::1
    
    # Hosts on local network are less restricted.
    #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap
    
    restrict hadoop101.com nomodify notrap noquery
    
    # Use public servers from the pool.ntp.org project.
    # Please consider joining the pool (http://www.pool.ntp.org/join.html).
    #server 0.centos.pool.ntp.org iburst
    #server 1.centos.pool.ntp.org iburst
    #server 2.centos.pool.ntp.org iburst
    #server 3.centos.pool.ntp.org iburst
    
    server hadoop101.com
    fudge hadoop101.com stratum 0
    
    #broadcast 192.168.1.255 autokey        # broadcast server
    #broadcastclient                        # broadcast client
    #broadcast 224.0.1.1 autokey            # multicast server
    #multicastclient 224.0.1.1              # multicast client
    #manycastserver 239.255.254.254         # manycast server
    #manycastclient 239.255.254.254 autokey # manycast client
    
    # Enable public key cryptography.
    #crypto
    
    includefile /etc/ntp/crypto/pw
    
    # Key file containing the keys and key identifiers used when operating
    # with symmetric key cryptography.
    keys /etc/ntp/keys
    
    # Specify the key identifiers which are trusted.
    #trustedkey 4 8 42
    
    # Specify the key identifier to use with the ntpdc utility.
    #requestkey 8
    
    # Specify the key identifier to use with the ntpq utility.

![复制代码][48304ba5e6f9fe08f3fa1abda7d326ab.png]

7、与本地ntpd Server同步一下

[root@hadoop102 ~]# ntpdate -u hadoop101.com
    15 Aug 11:33:35 ntpdate[8768]: adjust time server 192.168.1.101 offset 0.004621 sec

8、启动ntp服务

systemctl start ntpd

或

service ntpd start

9、设置开机启动

[root@hadoop102 ~]# systemctl enable ntpd
    Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.

10、查看状态

[root@hadoop103 ~]# ntpq -p
         remote           refid      st t when poll reach   delay   offset  jitter
    ==============================================================================
     hadoop101.com   .LOCL.           1 u   13   64    1    8.148   -2.581   0.000

[48304ba5e6f9fe08f3fa1abda7d326ab.png]: /images/20221120/b351263d85c54f93a5ca34d7d70ef895.png