Centos更新yum源

[1] 首先备份 /etc/yum.repos.d/CentOS-Base.repo 到其他文件夹

[2] 进入yum源配置文件所在文件夹

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

[3] 下载yum源配置文件，放入/etc/yum.repos.d/

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

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

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

[4] 运行yum makecache生成缓存

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