At present, there are six storage mechanisms in Liferay:
As of 6.1, DBStore has provided an alternative to the clusterability value added by using CMISStore and JCRStore. Hence, both of these latter stores can easily be deprecated and migrated to an alternative mechanism.
Moreover, due to LPS-25312, both FileSystemStore and AdvancedFileSystemStore risk concerns in scalability and need an overall refactor. Ultimately, only three storage mechanisms are necessary in Liferay: