Virtualization is a great tool for testing, learning, and general server skills practice. Using a virtualization tool like VirtualBox, you can install a server operating system within a virtual machine on your desktop or laptop. Once installed, you can pretty much do whatever you want with it and use it to learn more about your server in a safe environment.
For example, you may have a new application that you want to install on your server, but you want to make sure it will be fully compatible and run at a high performance level. You can test it by installing it within your virtual machine. Even if something goes wrong, neither your server nor your own computer will be affected.
These instructions assume you have already downloaded the CentOS ISO. To install CentOS in VirtualBox, do the following:
- Click the “New” button and then click “Next” to proceed
- Give your virtual machine a name
- For OS Type, select “Linux”, and for version, choose “Red Hat”
- On the memory screen, choose a reasonable amount. 512MB should be enough.
- Choose “Create a new hard disk” and go through the disk creation wizard.
- Once you are finished click “Finish”
- Click the “Settings” button
- Choose “Storage” from the side options
- In the Storage Tree, click the first icon next to “IDE Controller” to add a CD/DVD device
- When it asks you if you want to choose one, click “Choose disk”
- When your file dialog appears, choose the CentOS ISO
- Click the System option on the left
- In the Boot Order section, make sure CD/DVD-ROM is selected and moved to the top
- Click “OK”
- Click the “Start” button
At this point, VirtualBox should boot the CD. If you are using the LiveCD, it will boot CentOS, and you can then install from the desktop. If it is an install-only CD, just go through the normal installation process. When it is fully installed, you can change the boot order in VirtualBox to make it boot to the hard disk first. You should now have a working virtual machine of CentOS.