參考文檔 https://blog.csdn.net/inslow/article/details/54177191

國內主要開源的開源鏡像站點應該是網易和阿裏雲了。

修改為163yum源-mirrors.163.com

1、首先備份系統自帶yum源配置文件/etc/yum.repos.d/CentOS-Base.repo

[root@localhost ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

2、進入yum源配置文件所在的文件夾

[root@localhost ~]# cd /etc/yum.repos.d/

3、查看CentOS系統版本

[root@localhost ~]# lsb_release -a

4、下載163的yum源配置文件到上面那個文件夾內

CentOS7

[root@localhost yum.repos.d]# wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

CentOS6

[root@localhost yum.repos.d]# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

CentOS5

[root@localhost yum.repos.d]# wget http://mirrors.163.com/.help/CentOS5-Base-163.repo

5、運行yum makecache生成緩存

[root@localhost yum.repos.d]# yum makecache

6、這時候再更新系統就會看到以下mirrors.163.com信息

[root@localhost yum.repos.d]# yum -y update
已加載插件：fastestmirror, refresh-packagekit, security
設置更新進程Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* extras: mirrors.163.com
* updates: mirrors.163.com

修改為阿裏yum源-mirrors.aliyun.com

1、首先備份系統自帶yum源配置文件/etc/yum.repos.d/CentOS-Base.repo

[root@localhost ~]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

2、查看CentOS系統版本

[root@localhost ~]# lsb_release -a

3、下載ailiyun的yum源配置文件到/etc/yum.repos.d/
CentOS7

[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

CentOS6

[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo

CentOS5

[root@localhost ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo

4、運行yum makecache生成緩存

[root@localhost ~]# yum makecache

5、這時候再更新系統就會看到以下mirrors.aliyun.com信息

[root@localhost ~]# yum -y update
已加載插件：fastestmirror, refresh-packagekit, security
設置更新進程Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com

修改CentOS默認yum源為國內鏡像