centos 7换源
yum install -y wget
wget -P /etc/yum.repos.d/ wget http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
cd /etc/yum.repos.d/
mkdir bak
mv CentOS* bak
yum makecache
yum install -y wget
wget -P /etc/yum.repos.d/ wget http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
cd /etc/yum.repos.d/
mkdir bak
mv CentOS* bak
yum makecache