Windows 8 to get new 'resilient' file system

Microsoft has detailed a next-generation file system being introduced in Windows 8, which will maintain backwards compatibility for applications, while adding support for new storage technologies and scenarios such as large-scale storage deployments.

In its Building Windows 8 blog, Microsoft detailed how the new Resilient File System (ReFS) will build on the foundations of the current NTFS, but deliver in Windows 8 greater protection against data corruption from errors or power loss, while optimising for extreme scale.

The firm said it is maintaining compatibility with those NTFS features that are most widely adopted, while discontinuing support for some features that it claims are less often used, in order to reduce complexity.

However, support for NTFS will also be retained in Windows for the foreseeable future, so customers can continue to use it if they have any applications that require any of the deprecated features.

ReFS is based on a new storage engine at its lowest level that uses B+ tree structures to store data, Microsoft said. These tree structures can be large and multi-level, providing the required scalability for the file system.

But above this level, Microsoft is retaining the file system APIs from NTFS, even down to the level of reusing the code for the Windows file system semantics to ensure a high degree of compatibility with the features of NTFS that are being carried forward.

"We didn't start from scratch, but re-imagined [the file system] where it made sense and built on the right parts of NTFS where that made sense," said Surendra Verma, development manager on Microsoft's Storage and File System team.

"Above all, we are delivering this in a pragmatic manner consistent with the delivery of a major file system – something only Microsoft has done at this scale."