也希望本文可以帮到有需要的人。
1.查看系统预装的yum rpm包：
rpm - qa | grep yum
以下是我的系统预装的软件（我的是redhat7）：
[root@localhost ~]# rpm -qa|grep yum
yum-langpacks-0.4.2-4.el7.noarch
yum-metadata-parser-1.1.4-10.el7.x86_64
yum-3.4.3-132.el7.centos.0.1.noarch
yum-utils-1.1.31-34.el7.noarch
yum-plugin-fastestmirror-1.1.31-34.el7.noarch
yum-rhn-plugin-2.0.1-5.el7.noarch
PackageKit-yum-1.0.7-5.e17.x86_64
2.卸载上面的rpm包：
rpm -e yum-langpacks-0.4.2-4.el7.noarch --nodeps
后面的卸载方式依照上面。
3.更改yum仓库：
cd /etc/yum.repos.d/
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
下載文件：
http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
其他对应即可。
下载centos 的rpm包：
对应你卸载的rpm包下载：（我卸载了这些所以我下载这些）
yum-langpacks-0.4.2-4.el7.noarch
yum-metadata-parser-1.1.4-10.el7.x86_64
yum-3.4.3-132.el7.centos.0.1.noarch
yum-utils-1.1.31-34.el7.noarch
yum-plugin-fastestmirror-1.1.31-34.el7.noarch
yum-rhn-plugin-2.0.1-5.el7.noarch
PackageKit-yum-1.0.7-5.e17.x86_64
下载地址：
http://mirrors.163.com/centos/7/os/x86_64/Packages/
4.安装rpm包：
rpm -ivh yum-3.4.3-132.el7.centos.0.1.noarch.rpm yum-plugin-fastestmirror-1.1.31-34.el7.noarch.rpm
上面两个包要一起安装，不然会有依赖错误
在安装其他的rpm包
5.清除缓存：
yum clean all
6.建立緩存：
yum makecache
如果出現一下報錯：
将/etc/yum.repos.d/CentOS7-Base-163.repo 文件中的$releasever替换成你的系统版本号即可。
到此yum已经替换好了。
可以用yum安装软件了：
[root@localhost ~]# yum install telnet
Loaded plugins: fastestmirror, langpacks, product-id, search-disabled-repos, subscription-
: manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package telnet.x86_64 1:0.17-59.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
===============================================================================================
Package Arch Version Repository Size
===============================================================================================
Installing:
telnet x86_64 1:0.17-59.el7 base 63 k
Transaction Summary
===============================================================================================
Install 1 Package
Total download size: 63 k
Installed size: 113 k
Is this ok [y/d/N]: y
Downloading packages:
telnet-0.17-59.el7.x86_64.rpm | 63 kB 00:00:02
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : 1:telnet-0.17-59.el7.x86_64
Verifying : 1:telnet-0.17-59.el7.x86_64
Installed:
telnet.x86_64 1:0.17-59.el7
Complete!
附上我的yum仓库文件：
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base - 163.com
#mirrorlist=http://mirrorlist.centos.org/7=$releasever&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos/7/os/$basearch/
gpgcheck=1
gpgkey=
#released updates
[updates]
name=CentOS-$releasever - Updates - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos/7/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - 163.com
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos/7/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - 163.com
baseurl=http://mirrors.163.com/centos/7/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
欢迎大家指正错误！！
更多YUM相关教程见以下内容：