centos7 modify the source yum Ali mirror

Reference blog:

• https://blog.csdn.net/kxwinxp/article/details/78578492

• https://blog.csdn.net/inslow/article/details/54177191

You need to operate under the root account

• The new system may need to open the network configuration, as follows

ip address
#查看网络连接设备
#可以看到两个设备： 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 
2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 
#那么，有线网就是叫enp1s0啦，（虚拟机一般为 ens33 ）

// 打开有线网配置 
vi /etc/sysconfig/network-scripts/ifcfg-enp1s0  
// 最后一行，修改为YES 
ONBOOT=YES 
// 重启网络服务 
systemctl restart network.service

• The backup system image source

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

• Download Ali mirror source, if not wget, use yum install wgetthe installation

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

• Run yum makecache generate cache

yum makecache

• Then update

yum update

• Increase epal source

// 安装epel源
yum install epel-release
// 修改为阿里的epel源
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

// 安装yum源优先级管理工具
yum install -y yum-priorities
// 添加优先级（数字越小优先级越高）
vim /etc/yum.repo.d/epel.repo
priority=88
// 添加优先级（这个数要小于epel里的88即可）
vim /etc/yum.repo.d/Centos-7.repo
priority=6

// 开启yum源优先级功能
vim /etc/yum/pluginconf.d/priorities.conf
// 确保文件内容包含如下：
[main]
enabled=1