【Vagrant】default: Warning: Remote connection disconnect. Retrying... が何度も出て起動しない場合

$ vagrant up ==> default: Booting VM... ==> default: Waiting for machine to boot. This may take a few minutes... default: SSH address: 127.0.0.1:2222 default: SSH username: vagrant default: SSH auth method: private key default: Warning: Connection timeout. Retrying... default: Warning: Remote connection disconnect. Retrying... default: Warning: Remote connection disconnect. Retrying... default: Warning: Remote connection disconnect. Retrying... default: Warning: Remote connection disconnect. Retrying... default: Warning: Remote connection disconnect. Retrying... ...

なかなか起動してくれない。
試しにタイムアウトの秒数を増やしてみた。

config.vm.boot_timeout = 100

動いた。

Error: Connection refused. Retrying... · Issue #3329 · mitchellh/vagrant · GitHub

ssh - Vagrant :: Unable to run vagrant up; Connection timeout. Retrying - Super User