Dell Unity Data Reduction and/or Advanced Deduplication can be enabled on a supported storage resource at any point in time. This can be completed in Unisphere from the properties window of the storage resource, or by utilizing Unisphere CLI or REST API. Enabling data reduction on File storage resources created prior to UnityOS  4.2 is not supported. When data reduction and/or Advanced Deduplication is enabled on an existing resource, no data on the storage resource is passed through the data reduction algorithm at that time. All previously written data is left in its original state, and only new writes or overwrites are subject to the data reduction algorithm. To achieve savings on existing data within a Block storage resource, the user can utilize the Local LUN Move option, which is outlined below. For File resources, the methods to move File data include host-based migration to a Dell UnityOS 4.2 or later Thin File System, VMware vMotion for VMs created on NFS Datastores, or Dell Unity Asynchronous Replication.