1. A method for controlling a data de-duplication system to perform garbage collection, the method comprising: accessing a first list of tags, the first list of tags being a list of active tags associated with a data object stored in a data de-duplication system object store, where accessing the first list of tags comprises acquiring information about tags associated with active file namespaces associated with the de-duplication system by acquiring information from active namespace snapshot metadata acquired during a replication performed by the de-duplication system; accessing a second list of tags, the second list of tags being a list of tags in the data de-duplication system object store, where accessing the second list of tags comprises acquiring information about tags actually present in the data de-duplication system object store by one or more of, accessing the object store via an object store Application Programming Interface (API) that is configured to provide the second list, and accessing a real-time up-to-date list of tags maintained by the data de-duplication system; and performing garbage collection in the de-duplication system by reclaiming space in the data de-duplication object store by selectively deleting a tag present in the data de-duplication object store upon determining that the tag present in the data de-duplication object store is in the second list of tags but is not in the first list of tags, where deleting the tag comprises one or more of, physically deleting the tag and logically deleting the tag through reference count manipulation including delaying the deleting of the tag present in the data de-duplication system object store for a period of time sufficient to allow a race condition associated with deleting the tag to be resolved.