yum安装时 后面加 --nogpgcheck
yum update
错误提示 Error: initscripts conflicts with centos-release-7-4.1708.el7.centos.x86_64 意思是相冲突了，既然冲突就排除掉；定位到错误关键词为 initscripts；
yum update --exclude=kernel* --exclude=centos-release* --exclude=initscripts*
此命令（yum update –exclude=kernel* –exclude=centos-release* –exclude=initscripts*）模式下升级方可正常
或者：rpm -e redhat-release-server-7.0-1.el7.x86_64 --nodeps 删除冲突的包