I want to make a web host based on clustered hosting. Basically this would be so that customers can grow a lot and still only consume some of the cluster's resources. Does anyone here know anything about clustered hosting, either how to do it or what software to use?

In reality you should have prior knowledge of clustered hosting to be able to provide a decent service to customers. You can't build a hosting business on technology you don't understand yourself without spending large amounts of money on consultants and other third parties to help you out. Unless you have a large bank roll I'd suggest you start with something a lot simpler such as a reseller plan and learn about the hosting industry and the technologies involved before investing in your own equipment and network.

First, I know how to host a shared environment. I would like to take that knowledge further though. I want to evaluate whether it is a reasonable task to build a server cluster. I would obviously due testing first. I would not be doing much investing either. I would use dedicated servers from layeredtech.

Dolbz was trying to make a very valid point.

If you are aiming towards "clustered" hosting the way H-Sphere does it, then that is all you will need. A bunch of servers and H-Sphere Licenses.

If, on the other hand you are aiming towards a Load Balanced cluster you will need much more experience than just leasing servers from layeredtech.

Load Balancing, Firewalls, NAT, Shared Storage, there's a lot more to Load Balancing a cluster than just deciding what software to use.

I want to evaluate whether it is a reasonable task to build a server cluster.

Well, I suppose it depends on your definition of "reasonable". if your target market is customers who are willing to actually pay a "reasonable" price for true clustered hosting service.. then you might have a chance at success if you are good at marketing.

However, if you are just going to throw together a bunch of servers, put a $1/month price on it, and hope that makes you better then everyeone else, then you have no chance for success.

I would not be doing much investing either. I would use dedicated servers from layeredtech.

A true clustered environment requires a significant investment in both time (learning how everything works) and money (lots of servers, software, and admins to keep it all working).

If clusted for you is about failover, I like the way these guys do it: http://www.hostingzoom.com/web/technology.html

:)
D