The title probably makes little sense, so here is an example.
I have a file hosting site, that serves a large amount of semi-randomly accessed files.
The setup is as follows:
High horsepower front-end +DB server that also does encoding for files that need encoding
Fresh file server, which stores newly uploaded content, thats probably (and usually) rapidly accessible, which has 500GB of raided SSD storage, that can push over 3GBit of traffic.
3 cheap node servers, containing 2 x 750GB SATA drives in raid1, where files older than 2 weeks are archived, from the SSD server (mentioned above).
Files on each server are accessed via subdomains (via modsec) in a straight forward fashion (server1.domain.com, server2.domain.com, etc)
Where I have the problem is this. I introduced a "premium" service where people pay a small fee every month, and get ad-free, quick accesses to stuff on the site. Once they are logged in, they access same files via premium.server1.domain.com via a different modsec script, with a different pass phrase. That all works fine and dandy.... except the cheap node servers are all IO bound, so accessing the files on them via a different, unsaturated network makes no difference, since it cannot read off the drive fast enough.
What would be a good way to make files on the site be accessible via 2 different network routes, 1 of which will be saturated (the "free network") while all other files are on an un-saturated "premium" network?