flexible storage

[Joshua Stoutenburg]

Hey people,

First, some context:

I'm running Ubuntu 10.04 LTS Server (32-bit) on a "not-so-old" Dell
box with an Intel Pentium 4 CPU 3.00GHz PAE and 2517 MB memory.

To make the most of the server, I chose to virtualize, but the
hardware apparently doesn't support KVM, so I went with I'm familiar
with, VirtualBox. This will allow me to create some VMs to host
internet services, and other VMs for playing around. Plus, the VMs can
be exported and imported easily, minimizing the amount of
administration to recreate the setup. Here's how I set it up:
http://blog.jstoutenburg.com/2011/08/ubuntu-1004-lts-virtualbox-412.html

Now, the question:

There are two challenges I will eventually run into, especially if
something I do on the servers ends up attracting a lot of visitors: 1)
storage space and 2) load.

Could somebody explain how to overcome these obstacles, or point me to
some good reference material?

NOTE: Not looking for commercial solutions. That would take all the
fun out of it!