修改CentOS默认yum源为mirrors.163.com
1.首先备份系统自带yum源配置文件/etc/yum.repos.d/CentOS-Base.repo
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2.进入yum源配置文件所在的文件夹
cd /etc/yum.repos.d/
3.下载163的yum源配置文件到上面那个文件夹内
CentOS7：
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
CentOS6：
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
CentOS5：
wget http://mirrors.163.com/.help/CentOS5-Base-163.repo
4.运行yum makecache生成缓存
yum makecache
5.这时候再更新系统就会看到以下mirrors.163.com信息
[root@localhost yum.repos.d]# yum -y update 已加载插件：fastestmirror, refresh-packagekit, security 设置更新进程Loading mirror speeds from cached hostfile * base: mirrors.163.com * extras: mirrors.163.com * updates: mirrors.163.com
修改CentOS默认yum源为mirrors.aliyun.com
1、首先备份系统自带yum源配置文件/etc/yum.repos.d/CentOS-Base.repo
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2、下载ailiyun的yum源配置文件到/etc/yum.repos.d/
CentOS7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
CentOS6
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
CentOS5
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
3、运行yum makecache生成缓存
yum makecache
4、这时候再更新系统就会看到以下mirrors.aliyun.com信息
[root@localhost ~]# yum -y update 已加载插件：fastestmirror, refresh-packagekit, security 设置更新进程Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com
原文：https://www.cnblogs.com/yanwanglol/p/8987969.html