【更新】Centos 7已於2024年6月30日停止維護，更換yum源解決yum404問題

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

curl -o /etc/yum.repos.d/CentOS-Base.repo \
http://mirrors.vpnforgame.net/centos/7/CentOS-Base.repo

curl -o /etc/yum.repos.d/epel.repo \
http://mirrors.vpnforgame.net/epel/7/epel.repo

yum clean all

yum makecache