Red Hat 7.3 配置使用CentOS 7.3 Yum 源

redhat 的更新包只对注册的用户生效，所以我们自己手动更改成CentOS 的更新包，CentOS几乎和redhat是一样的，所以无需担心软件包是否可安装，安装之后是否有问题，另外CentOS公司去年已经被Redhat 收购了，不说费话了，我们还是来操作吧！
1、首先查看redhat 7.3系统本身所安装的那些yum 软件包：

[a@localhost]$ rpm -qa | grep yum
PackageKit-yum-1.0.7-6.el7.x86_64
yum-3.4.3-150.el7.noarch
yum-metadata-parser-1.1.4-10.el7.x86_64
yum-rhn-plugin-2.0.1-6.el7.noarch
yum-langpacks-0.4.2-7.el7.noarch
yum-utils-1.1.31-40.el7.noarch

注意权限！！
删除yum包

[root@localhost]# rpm -e PackageKit-yum-1.0.7-6.el7.x86_64 --nodeps
[root@localhost]# rpm -e yum-3.4.3-150.el7.noarch --nodeps
[root@localhost]# rpm -e yum-metadata-parser-1.1.4-10.el7.x86_64 --nodeps
[root@localhost]# rpm -e yum-rhn-plugin-2.0.1-6.el7.noarch --nodeps
[root@localhost]# rpm -e yum-langpacks-0.4.2-7.el7.noarch --nodeps

右上角选择上网，保证可以联网，火狐+百度的测试

网易163网络源地址：http://mirrors.163.com/
这里寻找你要的包，
1，选centos
2，选择系统版本7.3.1611/
3，选择包类型（系统） os/
4，系统位数 x86_64/
5，包 Packages/
6，ctrl+f 搜索yum
7，一般需要如下的几个包
yum-plugin-fastestmirror
yum-updateonboot
yum-utils
yum-metadata-parser
yum-3.4.3-150.el7

[root@localhost]# wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-40.el7.noarch.rpm
[root@localhost]#wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-updateonboot-1.1.31-40.el7.noarch.rpm
[root@localhost]#wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-utils-1.1.31-40.el7.noarch.rpm
[root@localhost]#wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
[root@localhost]#wget http://mirrors.163.com/centos/7.3.1611/os/x86_64/Packages/yum-3.4.3-150.el7.centos.noarch.rpm

安装

[root@localhost]# rpm -ivh yum-*
警告：yum-3.4.3-150.el7.centos.noarch.rpm: 头V3 RSA/SHA256 Signature, 密钥 ID f4a80eb5: NOKEY
准备中...                          ################################# [100%]
正在升级/安装...
   1:yum-metadata-parser-1.1.4-10.el7 ################################# [ 20%]
   2:yum-plugin-fastestmirror-1.1.31-4################################# [ 40%]
   3:yum-3.4.3-150.el7.centos         ################################# [ 60%]
   4:yum-updateonboot-1.1.31-40.el7   ################################# [ 80%]
   5:yum-utils-1.1.31-40.el7          ################################# [100%]

配置
[root@localhost ~]# vim /etc/yum.repos.d/CentOS-Base.repo
将版本号那里改为你之前选择的那个版本

[base]
name=CentOS-$releasever -Base
baseurl=http://mirrors.163.com/centos/7.3.1611/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7

#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.163.com/centos/7.3.1611/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7

[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.163.com/centos/7.3.1611/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.163.com/centos/7.3.1611/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/7.3.1611/os/x86_64/RPM-GPG-KEY-CentOS-7

清理之前源，保证只有一个配置文件

[root@localhost]# yum clean all
[root@localhost]# ls /etc/yum.repos.d/
CentOS-Base.repo

安装你需要的软件测试是否正常使用