I saw a post (I think it was here, however it may have been at the gnome forum) that had a link to a manual about taking several low end machines and clustering them to make them more like a decent box. I didn't subscribe to the thread, I should have because now I cannot find it anymore. If anyone can point me to that post or to information on how to do this I would be grateful.

It is called clustering.

What you need to do is look for cluster knoppix or paralell knoppix.

There are other distros that cluster but knoppix seems to be the most popular cluster variant.

I would suggest that you head over to distrowatch and search for distros that can cluster.

Thanks, that will help with the software end of it, but what hardware is all necessary, do I need a network switch or will a router work. I have never done much networking stuff.

linuxvirtualserver org , a LVS is a group of servers that appear to the client as one large, fast, reliable server. See the the Know-How at www austintek com/LVS/LVS-HOWTO

The LVS is like the "Linux HA" project at linux-ha org
which is providing Open Source high-availability software for Linux and other OSes since 1999.

The concept is just like raid-5 for harddisks, you can take some machines down for maintenance while the world-wide 24x7 web-services just keeps on running.

The above mentioned LVS is a different concept off virtual-machines than "VMware", "User-Mode-Linux", "Xen" , the german "Faumachine" and last but not least the "Linux-VServer"


With Regards
Openbsd

I used PARALLEL kinnopix and built my cluset of 2 p4 matchines , though nothing big nor did n do anything but i m just telling u its damn easy with parallel kinnopix

it also shows a detaild HOW-TO to help u build cluster when u boot your first PC ....

PARALLEL knoppix is a High Performance cluster, the focus is performance -

LVS linux and Linux-HA are High-Availability clusters, the focus is manageability and availability

Okay, thanks for all the info.
I don't think I will need an HA system yet because I am at school and they do not allow us to have our own web servers (we have a data transfer limit each week of 2GBs). I was thinking a HPC Beowulf (very low end) just to see what I could do.

From what I am reading on other webpages Parallel Knoppix is really easy and should work on a small router until I get a big switch, and I can also use it on my current PCs but still keep their current configuration.

At my school they are selling a bunch of old G3 macs and a bunch of old Sun Machines to students. If I bought a set of either of those would I connect them the same as I would PCs? I am having trouble finding a download for different architectures (LVS, Parallel Knoppix or others).

From what I am now finding out is that any linux will work as long as I install an MPI such as LAM. So this would make me think I can use any architecture compute I want and put any linux and MPI on it. I would assume all nodes should be of the same architecture so that distributed programs work.

It sound like a cool project. One word of warning though. Even if you have quite a small cluster say of the order 5 -10 think about the hidden costs if you have the machines on all the time. i.e your (or your parents if your still living at home) electric bill. Also make sure the ring main you are conecting to has enough spare capcity. If it is on the same ring as say your living room with loads of other electrical equipment and heaters e.t.c your could end up blowing the fuse. probably won't e an issue but keep an eye out.

I line in an on campus apartment(utilities included), which is why I am planning on doing this now. I didn't want to have to worry about the electric bill, but I suppose if I use too much it will raise the future costs of living there.
But I had not thought of blowing a fuse, I will have to pay attention to where I plug in. In my freshman year of undergraduate college I lived in a dorm where if two microwaves were turned on at the same time a whole section of the floor would lose power, and I would not want to relieve that.

I mainly wanted to experiment with some parallel programming, which is an area I have no experience. I have read some pages about how it is probably more cost efficient to buy a high end computer than to pay the electric bill for a cluster of POSes but then I wouldn't learn as much.

If you mainly want to learn and experiment with parrallel programs/programming
you can use VMware workstation or the free VMware server.

If you want to learn more, become an expert or just want to improve your skills
use UML, Xen or Faumachine virtualmachines.

User-Mode-Linux is also very easy to implement and customize

If your primary OS is Windows you can use coLinux virtual machines

VM computers/nodes will safes you a lot of time and money. Although you can have a lot of fun with the old Mac's and Sun's, with their first-class superior hardware.

Max 32 parallel processes - on shared resources
Free experimenting with parallel programming with Linux on innovative PowerPC hardware. Every user is limited to 3 hours of CPU-time and 32 parallel processes
max.

http://www-128.ibm.com/developerworks/linux/openpower/
Get remote, non-root, shared access with SSH to the latest POWER5 processor-based OpenPower servers.

University of Augsburg http://tuxppc.rz.uni-augsburg.de/
or
Peking University http://ppclinux.pku.edu.cn/index.php

it's simple, fast, and robust.

THis is exactly why I have 6 machines on a shelf not doing anything. My parents don't want me to run them all the time, and it kind of defeats the purpose to have to shut them down. I was going to use OpenMosix, which makes the machines act as one multi-CPU machine. It doesn't require any form of programming, as each process can only use the power of one processor, but it transfer's process's to other CPUs, depending on the load.