CentOS7下修改配置yum源

在CentOS 7中，修改YUM源可以通过以下步骤进行：

        1. 备份当前的YUM源: 

                cp -ar /etc/yum.repos.d /etc/yum.repos.d.bak

        2. 清除原有的YUM源文件:

                rm -f /etc/yum.repos.d/*

        3.以阿里云YUM源为例，创建一个新的YUM源配置文件:

                vim /etc/yum.repos.d/CentOS-Base.repo

        4. 将以下内容复制粘贴进去（根据您的需求选择合适的版本，比如centos7的阿里云源）:

[base]
name=CentOS-$releasever - Base - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
 
#released updates 
[updates]
name=CentOS-$releasever - Updates - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$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-$releasever - Extras - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

        5.保存文件并退出编辑器

        6. 清除YUM缓存并生成新的缓存

                sudo yum clean all

                sudo yum makecache