Some nots about virtual box configuration for linux test env.

Load the iso file

The path of the iso file should be set at the storage section of the virtual machine.

The defination of the screen

Add the addon plugin

Setting the network

bridge mode may not work properly sometimes (for example, the guest machine may not connect to network properly)

use the NAT plus the port forwarding to ssh local machine from the host machine (this is the most use cases)

This documents works for my case