vagrant up 启动时一直提示 remote connection disconnect retrying!
remote connection disconnect retrying
The guest machine entered an invalid state while waiting for it to boot. Valid states are 'starting, running'. The machine is in the 'unknown' state. Please verify everything is configured properly and try again. If the provider you're using has a GUI that comes with it, it is often helpful to open that and watch the machine, since the GUI often has more helpful error messages than Vagrant can retrieve. For example, if you're using VirtualBox, run `vagrant up` while the VirtualBox GUI is open. The primary issue for this error is that the provider you're using is not properly configured. This is very rarely a Vagrant issue.
然后他提示出了这些语句，然后我再vagrant ssh 发现又能进去了。。。怎么回事？