Patent ID: 7912866

Claim:
A system, comprising: a storage device configured to provide a storage space for data storage; and a file system configured to map file system content to said storage space for storage and to manage access to said storage device, wherein said file system content comprises a plurality of files and metadata records, wherein each of said metadata records is associated with a corresponding one of said plurality of files; wherein said file system is further configured to: detect an identity-modifying file operation specifying one or more source ones of said plurality of files and a destination one of said plurality of files; in response to detecting said identity-modifying file operation, for existing records of operations previously detected by said file system and responsively stored within metadata records associated with said one or more source files, store at least some of said existing records within a metadata record associated with said destination file; in response to storing an indication of said identity-modifying file operation within said metadata record associated with said destination file, store an indication of said identity-modifying file operation in a history stream; in response to detecting said indication of said identity-modifying file operation within said history stream, store a metadata record of said identity-modifying file operation in a database configured to store a plurality of entries, wherein said database is further configured to respond to a query of said plurality of entries; and examine entries in said database to compare a first valid signature of a second file to one or more unique signatures of a first file to establish that the first file is the ancestor of the second file based on a match between said first valid signature and one of said one or more unique signatures.