1. A method, comprising: receiving a query for information on files from a file system for a client node; determining metadata for files in a backup storage for the client node stored external to backup sets; processing at least one backup set in the backup storage for the client node to determine metadata for files included in at least one backup set; merging the determined metadata for files in the backup storage and for files included in at least one backup set to form merged metadata; executing the query against the merged metadata to determine files whose metadata satisfies the query; returning results including information from the merged metadata on the determined files; generating a token identifying the merged metadata; and receiving a subsequent query with the token from the client node, wherein the token is used to execute the subsequent query against the merged metadata identified by the token.