如图：下载这个ceph/ubuntu-xenial
命令格式： vagrant box add ceph/ubuntu-xenia {链接}
ceph/ubuntu-xenial.box
命令实例：
vagrant box add ceph/ubuntu-xenial https://app.vagrantup.com/ceph/boxes/ubuntu-xenial
vagrant box add ceph/ubuntu-xenial https://app.vagrantup.com/ceph/boxes/ubuntu-xenial
==> box: Loading metadata for box 'https://app.vagrantup.com/ceph/boxes/ubuntu-xenial'
This box can work with multiple providers! The providers that it
can work with are listed below. Please review the list and choose
the provider you will be working with.
1) libvirt
2) virtualbox
Enter your choice: 2
==> box: Adding box 'ceph/ubuntu-xenial' (v0.0.1) for provider: virtualbox
#下载地址
box: Downloading: https://vagrantcloud.com/ceph/boxes/ubuntu-xenial/versions/0.0.1/providers/virtualbox.box
box: Download redirected to host: vagrantcloud-files-production.s3.amazonaws.com
box: Progress: 0% (Rate: 99k/s, Estimated time remaining: 4:28:13)
用其他方法下载：(比如迅雷)
https://vagrantcloud.com/ceph/boxes/ubuntu-xenial/versions/0.0.1/providers/virtualbox.box
添加本地下载好的box文件
vagrant box add ceph/ubuntu-xenial C:\Users\Administrator\Downloads\cephubuntu-xenial.box
vagrant box add "name" C:\Users\Administrator\Downloads\cephubuntu-xenial.box
查看所有box
vagrant box list
初始化;
vagrant init ceph/ubuntu-xenial .
A `Vagrantfile` has been placed in this directory. You are now
ready to `vagrant up` your first virtual environment! Please read
the comments in the Vagrantfile as well as documentation on
`vagrantup.com` for more information on using Vagrant.
启动：
vagrant up ceph/ubuntu-xenial
