While Windows 8 client machines will continue to use the NTFS filesystem, Microsoft's Surendra Verma has given us some details on Windows 8 Server's new "Resilient File System," or ReFS. ReFS is meant to maintain compatibility with the most frequently-used features of NTFS, including Bitlocker encryption compatibility, Access Control Lists (ACLs) to control permissions, change notifications, symbolic links, and others, while shedding legacy features and picking up new ones to make it more useful and versatile on today's drives.

ReFS's server-oriented features work best in conjunction with Storage Spaces, which we discussed last week - if you don't remember, Storage Spaces is a feature available for both NTFS and ReFS volumes that can provide redundancy and pooled storage for numerous internal and external drives of different sizes and interfaces. Where Storage Spaces provide protection from disk failure, one of ReFS's primary goals is to combat data corruption, including situations where a write operation to the disk is interrupted, where data is written to the wrong area of a disk due to a software or firmware bug, and "bit rot," where data on infrequently accessed sections of a disk degrades over time.

ReFS  uses a feature called "integrity streams" to combat file corruption - when enabled, whenever a file is changed, the modified copy is written to a different area of the disk than that of the original file. This way, even if the write operation is interrupted and the modified file is lost, the original file is still intact. When combined with Storage Spaces, which can store a copy of all files in a storage array on more than one physical disk, ReFS gives Windows a way to automatically find and open an uncorrupted version of a file In the event that a file on one of the physical disks becmes corrupted.

To combat bit rot, ReFS (again, when combined with Storage Spaces) uses its "scrubbing" feature to read all copies of a file in the array and compare their metadata with one another. If a corrupted file is found anywhere in the array, it is replaced by a good copy. This is especially useful in the case of infrequently accessed data, which could become corrupt in between reads without anyone noticing.

Microsoft expects ReFS to be production-ready when Windows 8 Server is released to the public, but the filesystem will still be rolled out conservatively: it will first be available for Windows 8 Server, then for client operating systems, and then finally as an option for boot volumes. Whether ReFS will come to clients in a Windows 8 service pack or as part of another OS was not discussed, but Microsoft clearly intends it as a full-on replacement for NTFS in the long run - while it has been updated a few times over the years, the NTFS specification has been around since Windows NT 3.1 was introduced in 1993, and its last potential successor (WinFS) was among the many features cut from Windows Vista during its notoriously rocky five-year development cycle.

Source: Building Windows 8 Blog

Comments Locked


View All Comments

  • crispbp04 - Tuesday, January 17, 2012 - link

    Sounds Interesting. Can't wait for Win8 public beta! I'm running the developer preview on an MSI Windpad 110W
  • DarkUltra - Tuesday, January 17, 2012 - link

    I hope ReFS doesn't make Windows file operations even slower. I can hear my wd raptor is much less busy in Windows 7 vs XP, and loading the same apps from the same partition is considerably slower in Windows 7.


    Other windows 7 vs xp speed videos

  • eddman - Tuesday, January 17, 2012 - link

    I watched your first video and must say you should investigate things a little bit further before coming to such conclusions.

    Select as many files you want, right-click on one of them and then select properties; it'll immediately show their collective size.

    I don't know what windows 7 does after clicking on "show more details" but there must be some explanation for it. Your theory of MS slowing down 7 is ridiculous.
  • Andrew.a.cunningham - Tuesday, January 17, 2012 - link

    The source post doesn't talk much about performance, but I'd speculate that by the time ReFS gets down to clients, most computers will probably be shipping with SSDs - the performance increases there can mitigate all kinds of security and redundancy-related performance hits (disk encryption, etc.).
  • Klimax - Wednesday, January 18, 2012 - link

    This again??? I thought this i.. died already. Outdated mostly wrong with i... unusecases. An with heavy dose of subjective measurment.

    Really shows what some people know or want to believe and try to spout.

    1) Already saw - I would like to knów what author did to that system with 7. In no way it is general case what he had shown. In fact Explorer (7) is much better in working with thousands of files then Explorer (XP).
    2)Idiocy. Old, unusecase (tell me when you do such thing unless to prove a "point") and probabably just unoptimalised drivers. And doesn't prove a thing.
    3)Quite contrieved, but also the only one showing "problem", where it not for contrieved "usecase".

    To be frank, I had more problems with XP Explorer then with Explorer in 7. (Use TortoiseSVN and MediaInfo)
  • Jeff7181 - Saturday, January 21, 2012 - link

    And here's proof that Windows 7 is perfectly capable of enumerating and summing the size of the files in the system32 directory in a fraction of a second... make sure you have the audio turned on to hear when I hit enter.

  • djc208 - Tuesday, January 17, 2012 - link

    This sounds a lot like what WHS 2011 should have had to replace drive extender. Between the two it sounds like you basically get the same functionality as the original Drive Extended but in a more commercial friendly package.

    Might just need to wait for WHS 2013.
  • kkwst2 - Tuesday, January 17, 2012 - link

    Exactly what I was thinking. I'm sticking with original WHS for now...
  • DanNeely - Tuesday, January 17, 2012 - link

    Only problem is that WHS 1 is going out of support in just under a year 2013/01/08). Unless storage spaces is backported to WHS 2011 and released concurrent with win8 my replacement will probably be a different vendors product (and even then I'd be a bit nervous about using SS without it being through several months of general use to let other people find the bugs).
  • imaheadcase - Tuesday, January 17, 2012 - link

    Since when has "going out of support" mean anything to a OS user? You call MS about problems often?

    Its not like you are a corporation that needs it.

Log in

Don't have an account? Sign up now