将Centos的yum源更换为阿里云源

1、备份

mv/etc/yum.repos.d/CentOS-Base.repo/etc/yum.repos.d/CentOS-Base.repo.backup

2、下载新的CentOS-Base.repo 到/etc/yum.repos.d/

CentOS 5

wget-O/etc/yum.repos.d/CentOS-Base.repohttp://mirrors.aliyun.com/repo/Centos-5.repo

CentOS 6

wget-O/etc/yum.repos.d/CentOS-Base.repohttp://mirrors.aliyun.com/repo/Centos-6.repo

CentOS 7

wget-O/etc/yum.repos.d/CentOS-Base.repohttp://mirrors.aliyun.com/repo/Centos-7.repo

3、之后运行yum makecache生成缓存