According to one embodiment, a storage system (400) may include a gateway service (402), metadata service (404) and storage service (406) that each provide different storage system functions. Each service (402, 404 and 406) may include a plurality of servers that are functionally de-coupled from one another. De-coupled servers may service requests without regard to the operation of other servers of the same service. Such a de-coupled arrangement can allow a storage system (400) to be scaled to meet increasing demands, as servers may be added to a system, on a service by service basis, without necessarily re-indexing stored information or reconfiguring multiple instances of a server application. Further, backup servers may be easily added to the system to enable fault tolerance. Servers of a particular service (402, 404 and 406) may be accessed according to a quality of service policy.