1. Download VirtualBox and install.
Download link : https://www.virtualbox.org/wiki/Downloads
2. Download Linux. My default choice always CentOS.
Download link : https://www.centos.org/download/
I am choosing CentOS 7, as this round, I intend to setup TripleO to perform my OpenStack "lab". My CL210 subscription ended before the Support could fix the lab issue. Yes, this is not related to this article, but just my ranting.
3. Launch VirtualBox, and create new VM.
There's no CentOS selection, so I am choosing Redhat as the closest option.
Choose the right RAM size for your VM.
Create new virtual hard disk. I normally use the default settings.
This round I am using fixed-size.
Pick your disk size.
Hit the create button.
4. Network settings
Click on the Settings icon of your VM.
Go to Network. The NAT by default is setup. We will not touch it. This is the network adapter that allows the VM to connect to the Internet.
5. Install Linux in VM
Double click your VM. Browse to the Linux installation file, and click Start button.
Select "Install CentOS 7" and enter.
During the installation, when you try to click in the VM Windows, you'll see a pop up message like this, this is expected. When your mouse pointer is within the VM, it will "trapped" in the VM. To escape, just type the right "Ctrl" key.
Proceed to the installation step following the Wizard.
Your VM is ready to be used.
In case your VM unable to connect to Internet, use nmcli to check the device and connection, make sure they are up.