Data Deduplication does not currently work on ReFS volumes I discovered today.
The Resilient File System
Although ReFS inherited some of the NTFS code base initially, it is a different file system with different uses in mind. In fact, disk tools that work with the NTFS Master File Table (MFT) won’t be able to work with ReFS because ReFS has its own mechanism for keeping up with file metadata. ReFS is ideal for storing large amounts of data and can be leveraged for file shares. Applications that run locally on the server and rely on specific NTFS features may not work with ReFS. However, many may have no issues due to ReFS compatibility with many of the Win32 storage APIs. For example, Windows Deployment Services (WDS) explicitly requires NTFS because it relies on specific features in order to implement the RemoteInstall folder structure used for storing images. These are features that a conventional file server or data repository does not require. CHKDSK isn’t applicable to ReFS. Yes…I did just indicate that there’s no need to run CHKDSK on a ReFS partition. Are you feeling that the tool you’ve wanted to avoid for so long is now something you might want to hold onto…just in case? A love-hate relationship perhaps? The counselor is in. It’s okay to have those feelings if you have them. The truth is that in terms of ReFS partitions, ReFS doesn’t need CHKDSK because repair functionality is built-into the file system. Repair, if needed, occurs on-the-fly. Yep…there’s no need for extra tools to go fix corruption like with other file systems. And for what it’s worth, Windows Server 2012 contains improvements for CHKDSK. ReFS can use checksums to detect if data has changed since last written and is able to detect and recover from corruption quickly. In fact, when data is written to disk, it is written to a new location on disk rather than over the top of existing data. Once successfully written, the file system can free the space used by the old data stream. ReFS is able to recover from corruption within the file system rapidly without limiting availability of the volume. Further, ReFS may be used with clusters, Hyper-V, file shares, data archival, and many other uses.