- Download CentOS 6 Live DVD X86_64
- Start VirtualBox and create a new virtual machine. Select RedHat (64 bit) as OS. Make sure to allocate > 512M RAM to the VM.
- Power on VM. In First Run Wiard, browse to the downloaded Live DVD iso file.
- After the system starts, hit "Install to Hard Drive" on the desktop to start installation.
- Follow the instructions to install CentOS
- The hard drive for the VM will need partition. Select "Re-initialize" when prompted
- Restart after installation is complete (in VirtualBox VM settings, make sure it boots from hard disk instead of CD/DVD. Or it will still use the Live DVD)
It is important for the VM to have more than 512M RAM. Otherwise, the "Install to Hard Drive" won't run in GUI mode.