一，安装NTP
[root@localhost ~]# yum install ntp Loaded plugins: product-id, subscription-manager This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register. cdrom | 4.1 kB 00:00:00 Resolving Dependencies --> Running transaction check ---> Package ntp.x86_64 0:4.2.6p5-18.el7 will be installed --> Processing Dependency: ntpdate = 4.2.6p5-18.el7 for package: ntp-4.2.6p5-18.el7.x86_64 --> Processing Dependency: libopts.so.25()(64bit) for package: ntp-4.2.6p5-18.el7.x86_64 --> Running transaction check ---> Package autogen-libopts.x86_64 0:5.18-5.el7 will be installed ---> Package ntpdate.x86_64 0:4.2.6p5-18.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ============================================================================================= Package Arch Version Repository Size ============================================================================================= Installing: ntp x86_64 4.2.6p5-18.el7 cdrom 539 k Installing for dependencies: autogen-libopts x86_64 5.18-5.el7 cdrom 66 k ntpdate x86_64 4.2.6p5-18.el7 cdrom 82 k Transaction Summary ============================================================================================= Install 1 Package (+2 Dependent packages) Total download size: 687 k Installed size: 1.6 M Is this ok [y/d/N]: y Downloading packages: --------------------------------------------------------------------------------------------- Total 10 MB/s | 687 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : autogen-libopts-5.18-5.el7.x86_64 1/3 Installing : ntpdate-4.2.6p5-18.el7.x86_64 2/3 Installing : ntp-4.2.6p5-18.el7.x86_64 3/3 Verifying : ntpdate-4.2.6p5-18.el7.x86_64 1/3 Verifying : autogen-libopts-5.18-5.el7.x86_64 2/3 Verifying : ntp-4.2.6p5-18.el7.x86_64 3/3 Installed: ntp.x86_64 0:4.2.6p5-18.el7 Dependency Installed: autogen-libopts.x86_64 0:5.18-5.el7 ntpdate.x86_64 0:4.2.6p5-18.el7 Complete!