Distributed FS: MogileFS

> I don't know of any other products apart from S3 that could have made our file hosting as stress free as it is.

I think you're right about that part. Better solutions don't come off the shelf. Yet. :)

> What kind of scaling problems have you had?

the system I wrote at Mozy needed to scale to PBs of space and billions of files, so it was obvious that the mysql part would be a problem.

more generally I think mogile is in a pretty narrow niche: typically either you really need a lot of space and files, like flickr or facebook or ..., in which case mogilefs doesn't cut it, or you have a smaller data set but you want random access to your files in which case mogilefs also doesn't cut it.