linux時間同步

虛擬機時間同步：

[root@localhost ~]# date
Wed Jun 19 22:17:50 EDT 2019

時間與本地計算機時間快了12小時，查看網上相似問題方案是同步遠端服務器的時間

ntp經常使用服務器：

中國國家授時中心：210.72.145.44

NTP服務器(上海) ：ntp.api.bz

嘗試修改時間：

下載時間同步模塊

 1 [root@localhost ~]# yum -y install ntpdate
 2 Loaded plugins: fastestmirror
 3 base                                                     | 3.6 kB     00:00     
 4 extras                                                   | 3.4 kB     00:00     
 5 updates                                                  | 3.4 kB     00:00     
 6 (1/2): extras/7/x86_64/primary_db                          | 205 kB   00:00     
 7 (2/2): updates/7/x86_64/primary_db                         | 6.4 MB   00:05     
 8 Loading mirror speeds from cached hostfile
 9  * base: mirrors.zju.edu.cn
10  * extras: ap.stykers.moe
11  * updates: ap.stykers.moe
12 Resolving Dependencies
13 --> Running transaction check
14 ---> Package ntpdate.x86_64 0:4.2.6p5-28.el7.centos will be installed
15 --> Processing Dependency: libcrypto.so.10(OPENSSL_1.0.2)(64bit) for package: ntpdate-4.2.6p5-28.el7.centos.x86_64
16 --> Running transaction check
17 ---> Package openssl-libs.x86_64 1:1.0.1e-42.el7.9 will be updated
18 --> Processing Dependency: openssl-libs(x86-64) = 1:1.0.1e-42.el7.9 for package: 1:openssl-1.0.1e-42.el7.9.x86_64
19 ---> Package openssl-libs.x86_64 1:1.0.2k-16.el7_6.1 will be an update
20 --> Running transaction check
21 ---> Package openssl.x86_64 1:1.0.1e-42.el7.9 will be updated
22 ---> Package openssl.x86_64 1:1.0.2k-16.el7_6.1 will be an update
23 --> Finished Dependency Resolution
24 
25 Dependencies Resolved
26 
27 ================================================================================
28  Package           Arch        Version                       Repository    Size
29 ================================================================================
30 Installing:
31  ntpdate           x86_64      4.2.6p5-28.el7.centos         base          86 k
32 Updating for dependencies:
33  openssl           x86_64      1:1.0.2k-16.el7_6.1           updates      493 k
34  openssl-libs      x86_64      1:1.0.2k-16.el7_6.1           updates      1.2 M
35 
36 Transaction Summary
37 ================================================================================
38 Install  1 Package
39 Upgrade             ( 2 Dependent packages)
40 
41 Total download size: 1.8 M
42 Downloading packages:
43 Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
44 (1/3): ntpdate-4.2.6p5-28.el7.centos.x86_64.rpm            |  86 kB   00:00     
45 (2/3): openssl-1.0.2k-16.el7_6.1.x86_64.rpm                | 493 kB   00:00     
46 (3/3): openssl-libs-1.0.2k-16.el7_6.1.x86_64.rpm           | 1.2 MB   00:18     
47 --------------------------------------------------------------------------------
48 Total                                               96 kB/s | 1.8 MB  00:18     
49 Running transaction check
50 Running transaction test
51 Transaction test succeeded
52 Running transaction
53   Updating   : 1:openssl-libs-1.0.2k-16.el7_6.1.x86_64                      1/5 
54   Updating   : 1:openssl-1.0.2k-16.el7_6.1.x86_64                           2/5 
55   Installing : ntpdate-4.2.6p5-28.el7.centos.x86_64                         3/5 
56   Cleanup    : 1:openssl-1.0.1e-42.el7.9.x86_64                             4/5 
57   Cleanup    : 1:openssl-libs-1.0.1e-42.el7.9.x86_64                        5/5 
58   Verifying  : 1:openssl-1.0.2k-16.el7_6.1.x86_64                           1/5 
59   Verifying  : 1:openssl-libs-1.0.2k-16.el7_6.1.x86_64                      2/5 
60   Verifying  : ntpdate-4.2.6p5-28.el7.centos.x86_64                         3/5 
61   Verifying  : 1:openssl-libs-1.0.1e-42.el7.9.x86_64                        4/5 
62   Verifying  : 1:openssl-1.0.1e-42.el7.9.x86_64                             5/5 
63 
64 Installed:
65   ntpdate.x86_64 0:4.2.6p5-28.el7.centos                                        
66 
67 Dependency Updated:
68   openssl.x86_64 1:1.0.2k-16.el7_6.1   openssl-libs.x86_64 1:1.0.2k-16.el7_6.1  
69 
70 Complete!

嘗試同步遠程服務器

[root@localhost ~]# ntpdate -u 210.72.145.44

返回錯誤：

19 Jun 22:23:08 ntpdate[3361]: no server suitable for synchronization found

嘗試修改文件：

[root@localhost ~]# ntpdate -u ntp.api.bz
19 Jun 22:24:20 ntpdate[3362]: step time server 114.118.7.161 offset 3.555703 sec
[root@localhost ~]# date
Wed Jun 19 22:24:31 EDT 2019
[root@localhost ~]# cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
cp: overwrite ‘/etc/localtime’? y
[root@localhost ~]# ntpdate pool.ntp.org 
20 Jun 10:27:29 ntpdate[3366]: adjust time server 119.28.183.184 offset 0.079637 sec
[root@localhost ~]# date
Thu Jun 20 10:27:40 CST 2019

時間同步成功！