Microsoft are still working hard on getting Windows 8 ready to deploy. On their Building Windows 8 technology blog, their developers have started talking about a new file system that will be deployed with Windows Server 8.
The new file system, called ReFS (Resilient File System), will only be making its appearance on the Server variety of Windows rather than the desktop for a number of reasons. Primarily, while it is based on the NTFS APIs, in order to provide a more resilient and reliable system, a number of NTFS features considered key for the desktop (such as hard linking) will not be available.
In order to facilitate faster development of the file system, it re-uses a lot of code from NTFS. In fact, just about the entire file system interface from NTFS has been re-used; it is only the on-disk storage engine that has been completely re-written to support the new format.
As part of its resilience strategy, ReFS performs a number of auto-correcting functionality. Metadata is never overwritten – instead new metadata is written elsewhere. This prevents metadata failure when power is lost, for example. It is also possible to enable data verification and auto-correction, using checksums and copying valid data from a separate partition to correct invalid data on another disk. Corruption events are also handled more gracefully – instead of taking the file system offline, instead access to those corrupted parts is removed and the rest of the disk stays active.