Posted by
Waski_the_Squirrel on Monday, December 29, 2008 4:43:06 PM
Wouldn't it be great to have a
computer lab in your classroom? I don't care what age or subject you teach, it is certainly something that would be nice. Unfortunately, the typical school puts one computer in a room and that's it. If you're lucky, you may have a laptop lab available (but too small for your use) or you may be able to use the computer lab down the hall...if the computer teacher doesn't have a class that hour. I'm about to tell you how to get that computer lab at a low cost. This will be a technical posting. I'll get into usage in another entry.
Cost
Nothing in life is free. Though I'm about to save you a fortune, I'm not giving you a gift. When you set up your computer lab, you will need a few things:
- A good computer (this is your biggest expense, by far)
- Network cable and hangers (cost depends on size and geography of your room)
- Elderly computers (probably free: I rescued mine from a dumpster)
- Network switches (some cost, but you don't need to spend a lot)
- Tables (I rescued a motley assortment from storage)
I won't give a dollar figure. You may be able to get someone to donate some of this. You may retire your home computer to act as the "good" computer at school. There are just too many variables.
Lab Structure
Your "good computer" will act as a server. My server is a dual processor machine with 2 GB of memory, but I've used a Pentium 3 as a server (it was slow). I would advise the
LTSP.org website for more information. All of the computing for the entire lab will happen on the server. This isn't as bad as it sounds. Your computer spends most of its time just idling. You rarely use more than a fraction of its power and even that only for short times. This computer lab makes more complete use of your machine.
The machine will need 2 network cards. It probably has one and a second card can be purchased for $20 or less. One of these will connect to the internet.
The other connects to your first network switch. I needed a 100 ft length of network cable for this first connection. With different classroom geography, you may only need a few feet. Some people do this wirelessly, but the technology is not entirely reliable yet (for this use).
The switch then sends network cable to the client computers (terminals). You are limited only by your server. I used a 5-port switch. It runs 3 terminals and then connects to another switch which runs 3 more terminals on the other side of the room. You can certainly hook up far more terminals. I've heard of as many as 30 terminals. With a blade server, the sky is the limit!
The terminals themselves are "thin clients". They run their own display, keyboard, and mouse, but allow the server to do the rest of the computing. You can use old computers as terminals. You can also buy real terminals. I'm using Pentium I and II machines as my terminals. They need to be network bootable, which is the only obstacle. (A lot of old machines are not network bootable.)
To make them network bootable, I suggest having them boot from floppy. This is either really easy or a battle. You need to put the image for the chipset of your network card on a floppy through the
Rom-o-matic website. It becomes a battle when you can't decide what chipset you have! If you're lucky, the terminal is network bootable and there is no trouble at all.
Software
The catch with all of this is that you probably won't run Windows or Apple as your operating system. With both, you need to pay a licensing fee for every piece of software and every copy of the operating system running. That means in my lab, I would need to pay for 7 copies of everything, even though it's only on the server. It would be cheaper than a full computer lab, but way outside what I can afford.
You will run Linux. It's open-source and uses open-source software. Don't be afraid of "free". It is good software and has proven to be a viable competitor to Windows and Apple.
I run Fedora 10 on my computer. There are lots of great options for downloading it. Some versions make it really easy to set up the clients.
Were I to do this over, I would install the Ubuntu flavor of Linux. There is more software available and it is a bit more user friendly. More to the point, they have an
Edubuntu version designed specifically for education.
Other Considerations
I've destroyed my lab once or twice by accident. For this reason, I suggest doing regular backups of your server. If necessary, you can restore from the backup. You may also consider a back-up server. (I don't have one, but if your server dies due to hardware failure, you'll be glad.) Some people also have two servers share the duties of running the lab. When one server dies, the other can take over the full load.
You may also run into electrical issues. My room is over 40 years old. I have very few outlets. Right now I'm not up to code thanks to extension cords and the like. I need to get the school to add outlets.