Patent ID: 8037013

Claim:
A method of cooperatively locking storage, comprising: receiving an indication that a set of previous version data associated with a corresponding set of one or more writes to a data space by a journaling process configured to write to the data space previous version data comprising copies of writes to a protected entity is required to be retained; and adding to a set of stored metadata record identifiers associated with the set of previous version data, for each of a corresponding set of one or more metadata records associated with the set of one or more writes, an identifier that identifies the metadata record as one associated with a write that is to be retained by virtue of being associated with the set of previous version data, wherein for each write included in the set of one or more writes a corresponding metadata record identifier is included in the set of stored metadata record identifiers even if the metadata record identifier is included in one or more other sets of stored metadata record identifiers each associated with one or more other sets of writes associated with one or more other sets of previous version data required to be retained.