Patent ID: 7953704

Claim:
A method for taking a snapshot of a portion of a file system including files and directories, the method comprising: accepting, by a computer processor, at least one path that represents a portion of a file system which is less than the entire file system; accessing, by the computer processor, metadata associated with data that represents the top-most level of the at least one path, the metadata comprising information about the data, the information comprising a governance list, the governance list configured to comprise identifiers of a plurality of snapshots governing the data; obtaining, by the computer processor, a snapshot identifier identifying a snapshot; adding, by the computer processor, the snapshot identifier to the governance list of the accessed metadata prior to any modifications of the portion of the file system represented by the at least one path; receiving a request to modify a portion of a file to be modified within the portion of the file system represented by the at least one path; determining that the portion of the file to be modified is governed by a snapshot; copying the portion of the file to be modified prior to modifying the portion of the file to be modified; and creating an at least one indication in a snapshot metadata associated with the copied portion of the file, the at least one indication indicating that one or more references to unmodified portions of the file are not stored in the snapshot metadata.