1. A method for facilitating access to data in a wide area network, comprising: maintaining a scalable multi-node file system cache in a local cluster file system including multiple computing nodes; caching local file data in the cache by fetching file data on demand from a remote cluster file system into the cache over the network based on an application node signaling a gateway node to fetch the file data, wherein the local file data corresponds to file data in the remote cluster file system and the local namespace emulates the remote namespace; performing directory traversal of the cache for the remote cluster file system by creating a local directory structure on demand; creating directory entries in the cache on demand without creating the file objects, wherein the directory entries emulate the entries in the remote file system using information obtained from the cache; upon detecting that a requested file data is not in the cache, fetching file data on demand from the remote cluster file system into the cache over the network; and transferring local file data from the cache to the remote cluster file system over the network; wherein caching local file data in the cache further comprises: the application node of the local file system receiving a request for file access; the application node checking the cache for the requested file; upon detecting a cache hit, the application node accessing the file data in the cache; upon detecting a cache miss, fetching file data on demand from the remote cluster file system into the cache over the network, wherein fetching file data on demand further includes the gateway node fetching the file data from the remote cluster file system into the cache over the network for access by the application node.