I will be illustrating this task using VirtualBox on a Linux (Ubuntu 10.10) host and a Windows XP guest. The task with other combinations will vary, but the fundamental idea remains the same.
Step 1: Shut down the virtual machine
Make sure you don’t suspend the machine, because you won’t be able to access the settings.Step 2: Create a new virtual drive
A couple of steps are required to make this work. The first is to actually walk through the process of creating a new virtual machine. During this process you will define a new drive for that machine. Make sure you make the new drive the size you want for the additional drive. By default you will create a 10GB drive — if that will serve as enough additional space for your second virtual drive, leave it as is. If you need more space, adjust it during the creation of the virtual machine.Once the new virtual machine is created, you can then go back and delete the new virtual machine. This process will leave behind the newly created drive that you can then use for your original virtual machine.
The next phase of this step is that you need to open the settings of your virtual machine (the one you are adding the drive to) and then go to the Storage section (Figure A). Here you are going to add a new drive to this virtual machine. This new drive will be uninitialized and will have to be initialized later (from within the running Windows virtual machine — more on that in a bit).