ssh 链接失败报错如下：

Timed out while waiting for the machine to boot. This means that
Vagrant was unable to communicate with the guest machine within
the configured (“config.vm.boot_timeout” value) time period.
If you look above, you should be able to see the error(s) that
Vagrant had when attempting to connect to the machine. These errors
are usually good hints as to what may be wrong.
If you’re using a custom box, make sure that networking is properly
working and you’re able to connect to the machine. It is a common
problem that networking isn’t setup properly in these boxes.
Verify that authentication configurations are also setup properly,
as well.
If the box appears to be booting properly, you may want to increase
the timeout (“config.vm.boot_timeout”) value.

SSH 连接不上 ，我打开虚拟机查看，发现直接系统就没启动。怎么可能连接上虚拟机
kernel panic not syncing fatal exception

查看stackoverflow 前三种解决办法试过了 不过多赘述，可以去试试看
https://stackoverflow.com/questions/23293071/timed-out-while-waiting-for-the-machine-to-boot-when-vagrant-up

发现又是VirtualBox问题！！！ 我切换回6.1版本，成功解决问题

安装VirtualBox 6.1 出现的问题