US Patent 9886443 Distributed NFS metadata server

An architecture for implementing a distributed metadata system in a virtualization environment comprising a plurality of servers, wherein each server may access and operate upon the entirety of the metadata in the virtualization environment. In response to a request received at a server to operate upon the metadata, existing metadata associated with the request is read by the server. The server performs one or more updates based upon the retrieved metadata, and attempts to update the corresponding stored metadata. In some embodiments, attempting to update the stored metadata comprises reading the metadata again and comparing it to the originally retrieved metadata, and performing the update only if the newly retrieved metadata matches the originally retrieved metadata.