linux更改镜像源

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

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

yum clean all
这步如果报错Another app is currently holding the yum lock
ps aux|grep yum
把对应的进程kill掉

yum makecache