Nova官方资料地址：
https://www.openstack.org/software/releases/queens/components/nova
--> https://wiki.openstack.org/wiki/Nova
----> https://docs.openstack.org/nova/latest/admin/
----> https://docs.openstack.org/nova/rocky/admin/(current supported release)
nova 18.0.2.dev25
The OpenStack Compute service allows you to control an Infrastructure-as-a-Service (IaaS) cloud computing platform. It gives you control over instances and networks, and allows you to manage access to the cloud through users and projects.
Compute does not include virtualization software. Instead, it defines drivers that interact with underlying virtualization mechanisms that run on your host operating system, and exposes functionality over a web-based API.
计算服务提供了对虚机和网络的控制，让你可以通过用户或者项目来访问云。计算服务本身不含有虚拟化软件，通过定义驱动来和底层的虚拟化机制交互。