How would you build a cheap Virtual Server farm for home development? [closed]

I would like a virtual server farm at home, ideally 6 virtual servers, all for my own personal development. What is the cheapest way for me to achieve this? I'd ideally like to use VMWare as I use it at work.

Obvious questions:

How many physical servers? What processors? How much RAM? Disk space? Which product? What disk array?

Above all it has to be usable, I've had virtual server running on my laptop on top of Windows and it was basically unworkable. I don't want to build something to find it's slow and unusable.

I do intend to put Windows servers on to the VMs.

Many thanks

Firstly check that your CPUs support VMX flag (/proc/info). This is the hardware assisted virtualisation built into most new CPUs. (see http://en.wikipedia.org/wiki/Intel_VT#Intel_Virtualization_Technology_for_x86_.28Intel_VT-x.29) Almost any Core2 Duo or better.

This will speed up almost any virtualisation effort by a factor of 3-4x

Then if you have the cash buy an i7 range CPU - this has nested paging support (basically the VM is allowed to handle its own page faults). These are newish and give another 2x speed up.

Then download the Virtualbox.org Open Source edition. Put it on a Linux or FreeBSd box.

Then allocate about 256MB+ RAM, 8GB disk space and slap a CD into the drive, install as normal into the 8GB space and away you go.

You will need to be clever to get the servers visible from the outside - look at Network Bridging.

Linux Xen is supposed to be quite good too.

You should be able to do this all on one box, if you aren't expecting any great traffic to the server.

You don't say what stack you're intending on using. If it is a standard LAMP stack without a gui, everything should be quite usable on a single server. If you're talking IIS/Windows, perhaps not.

Also, when you say you want 6 servers, is that a 3-server MySQL cluster and a 3-Server apache cluster, or do you have something else in mind?

Also, whatever virtualization technology you are using, make sure you install the tools (ie. vmware tools, virtualbox tools), as they make everything more efficient and faster.