Abstract: Transitioning a data file in an archive system from read-write to write-once-read-many (“WORM”) is triggered by a control file rather than using a timeout approach or a overload approach. A storage manager may receive a series of archive instructions to write a data file to an archive. During this time, the archive file may be in a read-write state. The storage manager may receive a control file, which may be structured, such as an XML file. Receipt of the control file signals to an storage manager archive system that the data file has been written to the archive and triggers the storage manager to make the data file immutable by switching it from read-write state to WORM state.