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
[root@localhost ~]# 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
[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
3、运行yum makecache生成缓存
[root@localhost ~]# 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