How To Install VirtualBox on CentOS 6.3 x64
Step 1 - Installation
yum -y groupinstall Desktop yum -y install qt qt-devel SDL-devel tigervnc-server gcc make kernel-devel export KERN_DIR=/usr/src/kernels/2.6.32-358.2.1.el6.x86_64 rpm -ivh http://download.virtualbox.org/virtualbox/4.2.10/VirtualBox-4.2-4.2.10_84104_el6-1.x86_64.rpm /etc/init.d/vboxdrv setup
Step 2 - Set VNC Server
Add these two lines to /etc/sysconfig/vncservers :
VNCSERVERS="0:root" VNCSERVERARGS="-geometry 1024x768"
If you do not want to run VNC as user root, and would like to create an encrypted tunnel, create a separate user, and add -localhost to VNCSERVERARGS above.
You would then have to create a tunnel using Putty or some other SSH client, and map localhost:port -> localhost:5901 tunnel, and restart vncserver service for changes to take effect.
Step 3 - Start VNC Server
service vncserver start
Step 4 - Download TightVNC Viewer and connect to your droplet's IP port 5900.
When connecting with TightVNC Viewer, remote host address would be in IP::PORT format:
Enter Your VNC Password from Step 2 above:
Step 5 - Upload your desired ISO Disk or Disk Image to be imported.
You can install any Linux / BSD / Windows OS with an uploaded ISO image.
If you have an existing Disk Image with filetypes such as VDI, VMDK, QCOW, or RAW, you can import them into VirtualBox.
Step 6 - Launch VirtualBox and Install Virtual Machines
Once you are connected via VNC, click Applications -> System Tools -> Oracle VM VirtualBox
Using VirtualBox, you can even install Windows operating system, but they will be limited to 1 CPU Core.
Here is Windows XP running in VirtualBox: