修改为阿里yum源-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

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

2、查看CentOS系统版本

[root@localhost ~]

# 

lsb_release -a

3、下载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、运行yum makecache生成缓存

[root@localhost ~]# yum makecache

5、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