1 Hosting Reseller

Can I run 2 hosts/servers on 1 domain?
I have one domain "www.example.com" and am currently running a forum on this domain on a host. This host is also storing some media files, eg: videos. I have recently obtained a reseller, and would like to have it under this domain as well "www.example.com". If I make accounts on this reseller, I would like to have the subdomains like so: "www.sub1.example.com", therefore I would need this reseller to be under my domain. Could I have my forums and reseller on the same domain?

Many major web sites have clustered servers. Haven't done too much research in to how it's done. Your site would be something like www.mysite.com, and the other server might be something like www.mysite.com/otherserver. Ran across a site that has a product that sets this up. http://www.octagate.com/divided_web_site.asp