I've been asked to setup a large, scalible, Internet fileserver setup. In a nut shell, users from around the world will be visiting a website, choosing a download and their location. Then the file will be pushed to them from the approriate server. All the backend code to drive this has been written.

My questions come in at the hardware level. If you were going to setup something like this what hardware factors would be most important to you for the servers? How would you handle the file storage? Would you use a NAS (or multiple NAS) and attach front-end servers to it?

Any thoughts would be appreciated..

The fileservers are going to be distributed around the world, right? Surely you'll want each server's storage to be local to it... or am I misunderstanding the question?

Correct.. the fileservers will be distributed around the world. There may be multiple servers in the same location serving the same files however. These files won't change much. Would it make sense to have local copies on each server.. or to have the servers share a copy of a central NAS?

Put local copies of all the files on each server. Otherwise, what's the point of having mirrors?