Centos7的Yum源搭建

1.备份系统自带的yum源配置文件

mkdir /root/yum_backup;
cp /etc/yum.repos.d/* /root/yum_backup/;

2.配置Yum源

wget -O /etc/yum.repos.d/CentOS-Base.repo  http://mirrors.aliyun.com/repo/Centos-7.repo

3.清理yum缓存并生成新的缓存

yum clean all;
yum makecache;

执行【yum clean all】命令有可能报错：

This system is not registered with an entitlement server. You can use subscription-manager to register

4.解决办法： 

1.首先，编辑subscription-manager.conf，把enabled值由1改为0，意为禁用 subscription-manager

vim /etc/yum/pluginconf.d/subscription-manager.conf

2.获取到一个名为CentOS-Base.repo的镜像源后，编辑所有的$releasever，替换为数字7，保存退出。  

sed -i 's/$releasever/7/g' /etc/yum.repos.d/CentOS-Base.repo

3.将repo镜像文件名CentOS-Base.repo名字改为redhat.repo，配置成功

mv CentOS-Base.repo redhat.repo

4.删除无用的镜像源

sed -i '/aliyuncs/d' /etc/yum.repos.d/redhat.repo

5.重新清理构建缓存

yum clean all;
yum makecache;

6.查看yum源

yum repolist all