I was speaking to one of our developers the other day, and he pointed me to the following paper: SEDA: An Architecture for Well-Conditioned, Scalable Internet Services as an example of the general philosophy behind the design of the Nutanix Distributed File System (NDFS).
Although the paper uses examples of both a webserver and a gnutella client, the philosophies are relevant to a large scale distributed filesystem. In the case of NDFS we are serving disk blocks to clients who happen to be virtual machines. One trade-off that is true in both cases is that scalability is traded for low latency in the single-stream case. However at load, the response time is generally better than a system that is designed to low-latency, and then attempted to scale-up to achive high throughput.
At Nutanix we often talk about web-scale architectures, and this paper gives a pretty solid idea of what that might mean in concrete terms.
FWIW., according to google scholar, the paper has been cited 937 times, including Cassandra which is how we store filesystem meta-data in a distributed fashion.