错误信息：
Vagrant was unable to mount VirtualBox shared folders. This is usually
because the filesystem "vboxsf" is not available. This filesystem is
made available via the VirtualBox Guest Additions and kernel module.
Please verify that these guest additions are properly installed in the
guest. This is not a bug in Vagrant and is usually caused by a faulty
Vagrant box. For context, the command attempted was:
mount -t vboxsf -o uid=1000,gid=1000 vagrant /vagrant
The error output from the command was:
mount: unknown filesystem type 'vboxsf'
解决方法：
# 安装 vbguest 插件
vagrant plugin install vagrant-vbguest
# 重启虚拟机
vagrant reload问题2：The following SSH command responded with a non-zero exit status.
Vagrant assumes that this means the command failed!
解决方法：（该方法未能解决我的问题，请跳转 windows 安装vagrant reload 失败； No Virtualbox Guest Additions installation found.）
虽然vagrant up启动报错，但是vagrant ssh还是能登陆虚拟机的，进入虚拟机后，执行如下命令
sudo rm -f /etc/udev/rules.d/70-persistent-net.rules对， 问题就处在在持久网络设备udev规则（persistent network device udev rules）是被原VM设置好的，再用box生成新VM时，，这些rules需要被更新。而这和Vagrantfile里对新VM设置private network的指令发生冲突。删除就好了。
再次启动就没问题了。。
