centos7 startx 切换远程桌面失败

解决：

1. 更换yum源

mv /etc/yum.repos.d{,.`date +%F`.bak}
mkdir -p /etc/yum.repos.d
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo && \
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo && \
yum makecache

2. 重新安装桌面环境软件包组

yum groupinstall -y "GNOME Desktop"

3. 设置开机启动默认模式：由字符界面改为图形界面

systemctl set-default graphical.target

4. 测试

startx