Methods and systems for managing data redundancy include registering certified commands, input files, output files, and arguments in an execution history list after execution of said certified commands. An existing output file is provided in response to execution of a first certified command that matches an entry in the execution history list. A file is deleted if the file is reproducible from another file using a second certified command. The deleted file is registered in a reproducible file list. The deleted file is reproduced upon request using the second certified command.