修改Centos默认yum源换成国内源

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
[ yum.repos.d]# wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
CentOS6
[ yum.repos.d]# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
CentOS5
[ yum.repos.d]# wget http://mirrors.163.com/.help/CentOS5-Base-163.repo

4、运行yum makecache生成缓存

[ yum.repos.d]# yum makecache