Linux版本：CentOS 7.9（以自己的具体版本选择对应的yum源文件）

以配置阿里云的CentOS 7的yum源为例

一、查看操作系统版本

cat /etc/os-release

cat /etc/system-release

二、切换到/etc/yum.repos.d/目录

cd /etc/yum.repos.d/

ls /etc/yum.repos.d/

三、备份原有的.repo文件

# 备份CentOS-Base.repo

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

# 创建备份文件夹

mkdir repo.bak

# 备份所有以.repo结尾的文件

mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/repo.bak

四、去官网下载对应版本的yum源文件

配置文件下载，网络源有很多，比如清华、阿里、网易以及其他很多高校都有，这里我们以阿里云的yum源为例，网站地址如下：

阿里云：http://mirrors.aliyun.com/repo/

网易：http://mirrors.163.com/.help/centos.html

清华：https://mirrors.tuna.tsinghua.edu.cn/help/centos/

• CentOS-7.repo
  

# 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 - mirrors.aliyun.com

failovermethod=priority

baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/

       http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/

       http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/

gpgcheck=1

gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 

#released updates

[updates]

name=CentOS-$releasever - Updates - mirrors.aliyun.com

failovermethod=priority

baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/

       http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/

       http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/

gpgcheck=1

gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 

#additional packages that may be useful

[extras]

name=CentOS-$releasever - Extras - mirrors.aliyun.com

failovermethod=priority

baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/

       http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/

       http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/

gpgcheck=1

gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 

#additional packages that extend functionality of existing packages

[centosplus]

name=CentOS-$releasever - Plus - mirrors.aliyun.com

failovermethod=priority

baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/

       http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/

       http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/

gpgcheck=1

enabled=0

gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

 

#contrib - packages by Centos Users

[contrib]

name=CentOS-$releasever - Contrib - mirrors.aliyun.com

failovermethod=priority

baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/

       http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/

       http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/

gpgcheck=1

enabled=0

gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

五、创建并编辑CentOS-Base.repo文件

将CentOS-7.repo的内容粘贴到CentOS-Base.repo

vim CentOS-Base.repo

# i

# 将CentOS-7.repo的内容粘贴到CentOS-Base.repo

# esc :wq

六、yum清除缓存并重新建立

yum clean all && yum makecache

# 查看repo列表

yum repolist