In an aggregated file system, metadata is partitioned into multiple metadata volumes. On receipt of a file processing request, a file switch examines its mount entry cache to identify a target metadata volume that hosts the metadata of the requested file. The identification begins with mount entries at a root volume and continues recursively by examining a portion of the absolute pathname of the file until the target metadata volume is identified. Finally, the file switch forwards the request to a metadata server managing the target metadata volume. Since the identification process is carried out completely within the file switch, there is no need for multiple expensive network accesses to different metadata servers.