linux更改鏡像源

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
這步如果報錯Another app is currently holding the yum lock
ps aux|grep yum
把對應的進程kill掉

yum makecache