ReFS: The Next Generation File System for Windows

Operating systems rely on a file system to organize the clustered storage space. The file system maintains a database that records the status of each cluster. In essence, the file system shows the operating system in which cluster(s) a file is stored and where space is available to store new data. A file system can be thought of as an index or database containing the physical location of every piece of data on a hard drive. Today, NTFS (New Technology File System) is the most commonly used file system for hard drives in Windows. And as Microsoft continuous to improved Windows 8, they introduced the new file system, ReFS which stands for Resilient File System. The new file system was built in NTFS foundation and so compatibility will not be an issue. ReFS will be piloted  on Windows Server 8.

Windows 8 Blog detailed the key features of ReFS:

• Metadata integrity with checksums
• Integrity streams providing optional user data integrity
• Allocate on write transactional model for robust disk updates (also known as copy on write)
• Large volume, file and directory sizes
• Storage pooling and virtualization makes file system creation and management easy
• Data striping for performance (bandwidth can be managed) and redundancy for fault tolerance
• Disk scrubbing for protection against latent disk errors
• Resiliency to corruptions with “salvage” for maximum volume availability in all cases
• Shared storage pools across machines for additional failure tolerance and load balancing

The new file system will not replace the existing file system we know today at least for the time being. But as Surendra Verma explained in the post:

“With this in mind, we will implement ReFS in a staged evolution of the feature: first as a storage system for Windows Server, then as storage for clients, and then ultimately as a boot volume. This is the same approach we have used with new file systems in the past.”