|In this post, I'm going to show you how to create and setup a Virtual Machine, step by step, using the Open Source-based Oracle's VirtualBox 4.0.|
Next, you'll have to choose between a Dynamically expanding storage and a Fixed-size one.
In Dynamically expanding storage option, you'll have to specify the limit of the disk space you want to allocate to your VM. Physical hard disk space will be dynamically consumed, depending on the virtual one. So If you specify a limit of 10 Gigs for your VM, and have only used 3Gigs, your hard disk space will be 3Gigs short. In Fixed-size storage, you specify the disk space, and it's statically assigned to your VM, no-matter how much of it you actually use.
In short, Dynamically expanding storage is the clever choice, so go for it: