Windows 8's file system, ReFS, detailed in new blog post

Windows 8 users will have an all new file system, known as ReFS, when Microsoft's next operating system officially launches later in 2012. In a new post on Microsoft's official Windows 8 developer blog site, Surendra Verma, one of the development managers on the company's Storage and File System team, offers up more information on how ReFS (which stands for Resilient File System) will work. The current version of Windows uses NTFS  (New Technology File System) which has been used since Windows NT 3.1 back in 1993.

In the highly technical post Verma writes:

"... Windows file systems are accessed by the widest array of application and system software anywhere. ReFS takes that learning and builds on it. We didn’t start from scratch, but reimagined it where it made sense and built on the right parts of NTFS where that made sense. 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."

Verma says that some of the older file code has been reused, specifically for  " ... implementing the Windows file system semantics. This code implements the file system interface (read, write, open, close, change notification, etc.), maintains in-memory file and volume state, enforces security, and maintains memory caching and synchronization for file data. This reuse ensures a high degree of compatibility with the features of NTFS that we’re carrying forward."

ReFS will be introduced to Windows 8 users in different phases. Verma announced, " ... 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."

Earlier in January, Microsoft talked a bit about Storage Spaces, which will allow users to recover from a crash more quickly. In today's blog post Verma states:

We designed ReFS and Storage Spaces to complement each other, as two components of a complete storage system. We are making Storage Spaces available for NTFS (and client PCs) because there is great utility in that; the architectural layering supports this client-side approach while we adapt ReFS for usage on clients so that ultimately you’ll be able to use ReFS across both clients and servers.

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Microsoft needs to plan for NTSF to be around for a very long time, along with some type of file-type "converter" utility, so each type can recognize the other. ReFS may be used on tablets and smart phones; but NTSF will still be resident on laptops and desktops that will remain in use for many years. Microsoft needs to provide for easy data transfer between tablets and laptops/desktops; as tablets are auxiliary devices.

NTFS is a solid technology, this is the exact approach needed to advance it forward.

They could have kept the NTFS moniker and just called it NTFS+, but too many goofs that don't understand FS technology think NTFS is old or bad, yet there is still nothing outside of NTFS that provides the functionality and performance.

(Don't pull open Wikipedia and try to find some kludge that has one or two better options, especially when the WIkipedia list has columns that irrelevant to how NTFS works, and marks NTFS down for not having something it won't ever need.)

thenetavenger said,
NTFS is a solid technology, this is the exact approach needed to advance it forward.

They could have kept the NTFS moniker and just called it NTFS+, but too many goofs that don't understand FS technology think NTFS is old or bad, yet there is still nothing outside of NTFS that provides the functionality and performance.

(Don't pull open Wikipedia and try to find some kludge that has one or two better options, especially when the WIkipedia list has columns that irrelevant to how NTFS works, and marks NTFS down for not having something it won't ever need.)

NTFS is solid as well, and NO ONE would say anything about NTFS until they made an announcement about a NEW FS, NOW those goofs complain about how NTFS is outdated and needs a refresh.. yeah because NTFS has sooooooo many problems now.. (rolling eyes)

-- I still like your comment --

xpclient said,
Very impressive for data reliability but far too half-baked as it doesn't support many NTFS features.
Depends if the NTFS features are needed, or if there is a better approach to whatever said feature attempts to achieve.

xpclient said,
Very impressive for data reliability but far too half-baked as it doesn't support many NTFS features.

The features that aren't supported are driver features, not FS ones.
I agree that features such as encryption, compression and quotas are useful, but they can be added later. The FS itself is going to be tested on servers, which don't need most of these features; once it's mature, they can add features to the driver.

Aethec said,

The features that aren't supported are driver features, not FS ones.
I agree that features such as encryption, compression and quotas are useful, but they can be added later. The FS itself is going to be tested on servers, which don't need most of these features; once it's mature, they can add features to the driver.

No, these are all file system features.

xpclient said,
Very impressive for data reliability but far too half-baked as it doesn't support many NTFS features.

you people are amazingly dense, do you truly think they will abandon features of a FS that was created over 20 years ago.. and NOT expect them to come up with a decent replacement? NTFS features will be there, it will *NOT* be NTFS, it will be ReFS, but similar yet more robust functionality will STILL exist. It will require some changes, but I am SURE there will be an option to use NTFS instead to allow people time to make a transition..

What is wrong with you people, are you that retarded?

xpclient said,
Very impressive for data reliability but far too half-baked as it doesn't support many NTFS features.

you people are amazingly dense, do you truly think they will abandon features of a FS that was created over 20 years ago.. and NOT expect them to come up with a decent replacement? NTFS features will be there, it will *NOT* be NTFS, it will be ReFS, but similar yet more robust functionality will STILL exist.

What is wrong with you people, are you that retarded?

Is this the same filesystem that should arrive when Vista was first announced? At that time, it was called WinFS (http://en.wikipedia.org/wiki/WinFS). But after reading Wiki, it doesn't look like being similar at all.

At that time, they were explaining register is going out of Windows, somehow being connected totally with filesystem they were preparing. I guess we will have to watch register for a few years tho...

gregor said,
Is this the same filesystem that should arrive when Vista was first announced?

No, it is not. ReFS (BTW, bad name IMO, too similar to ReiserFS) is basically NTFS + extra layer on top that ensures integrity/consistency and better data protection (scrubbing, copy on write, additional metadata, storage pools).

Most of these concepts already exist and are in use in modern filesystems like ZFS. Microsoft just updated NTFS with these features, which are really required when we are talking about reliably storing large amount of data. This FS should be called NTFSv2 / SuperNTFS / etc... - it has nothing to do with the database-oriented file system, which was the initial idea of WinFS.

gregor said,
Is this the same filesystem that should arrive when Vista was first announced? At that time, it was called WinFS (http://en.wikipedia.org/wiki/WinFS). But after reading Wiki, it doesn't look like being similar at all.

At that time, they were explaining register is going out of Windows, somehow being connected totally with filesystem they were preparing. I guess we will have to watch register for a few years tho...


as I understand it, most of the planned features of winfs were merged into ntfs and the os (win vista/7) in terms of search etc.

kaczula said,

No, it is not. ReFS (BTW, bad name IMO, too similar to ReiserFS) is basically NTFS + extra layer on top that ensures integrity/consistency and better data protection (scrubbing, copy on write, additional metadata, storage pools).

Most of these concepts already exist and are in use in modern filesystems like ZFS. Microsoft just updated NTFS with these features, which are really required when we are talking about reliably storing large amount of data. This FS should be called NTFSv2 / SuperNTFS / etc... - it has nothing to do with the database-oriented file system, which was the initial idea of WinFS.

I think you have it backwords there. It's not NTFS+ new layer on top. It's a totally new base with NTFS compatibile APIs on top so that apps and clients/OS's that can access NTFS volumes can work with ReFS. There is NO NTFS in this, it's a brand new FS from the base, just sharing top level APIs for compatiblity.

kaczula said,

No, it is not. ReFS (BTW, bad name IMO, too similar to ReiserFS) is basically NTFS + extra layer on top that ensures integrity/consistency and better data protection (scrubbing, copy on write, additional metadata, storage pools).

Most of these concepts already exist and are in use in modern filesystems like ZFS. Microsoft just updated NTFS with these features, which are really required when we are talking about reliably storing large amount of data. This FS should be called NTFSv2 / SuperNTFS / etc... - it has nothing to do with the database-oriented file system, which was the initial idea of WinFS.

They rather replaced a layer in NTFS, not added one. And saying the new layer is on top is misleading - it's on the bottom, the top layer is the same, that is why it's compatible with anything that supports NTFS.

duddit2 said,

as I understand it, most of the planned features of winfs were merged into ntfs and the os (win vista/7) in terms of search etc.

Most WinFS features when into the newer (at the time) version of SQL Server and then even less of those made it into NTFS after that. WinFS is as good as dead now guys.

GP007 said,

Most WinFS features when into the newer (at the time) version of SQL Server and then even less of those made it into NTFS after that. WinFS is as good as dead now guys.

Many of the features were also implemented in Windows Vista and 7. For example the SQL-based search engine is a remnant of WinFS.

Lamp Post said,
Many of the features were also implemented in Windows Vista and 7. For example the SQL-based search engine is a remnant of WinFS.

Really? I thought that was from a german company Microsoft acquired AFTER announcing WinFS. I think the company was called FAST, and the first product to benefit was Sharepoint followed by Vista and then Win 7.

gregor said,
Is this the same filesystem that should arrive when Vista was first announced? At that time, it was called WinFS (http://en.wikipedia.org/wiki/WinFS). But after reading Wiki, it doesn't look like being similar at all.

At that time, they were explaining register is going out of Windows, somehow being connected totally with filesystem they were preparing. I guess we will have to watch register for a few years tho...


Well considering that WinFS was never a file system anyway no there is, no similarity between ReFS and WinFS.

kaczula said,

No, it is not. ReFS (BTW, bad name IMO, too similar to ReiserFS) is basically NTFS + extra layer on top that ensures integrity/consistency and better data protection - it has nothing to do with the database-oriented file system, which was the initial idea of WinFS.

Personally I like Reiser, it only STOPPED being used because the guy that created it is in prison for murder.. otherwise I use Reiser, it's pretty fast.. I rather like Reiser, and I am glad ReFS makes it seem like Reiser, I consider that a good thing.

Is this based at all on a database type style of file and folder lookups? A bit like WinFS or whatever the name of the last filesystem that got scrapped was called?

spUrr said,
Is this based at all on a database type style of file and folder lookups? A bit like WinFS or whatever the name of the last filesystem that got scrapped was called?

that is what i what to know.

spUrr said,
Is this based at all on a database type style of file and folder lookups? A bit like WinFS or whatever the name of the last filesystem that got scrapped was called?

No it's based on nested b-trees .
Not exactly a database engine, but the filesystem engine will be able to scan index and retrieve the data with greater efficiency and scale.

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!

Not hapenning so soon.

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!
exFAT is writable and readable in OSX

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!

A ReFS is volume is accesible from any OS that supports NTFS.

They have only replaced the LOWER NTFS layer with the new ReFS layer. So the higher level API is compatible with NTFS

Pretty Neat

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!
More BS from ignoramuses that don't know what they're taking about? Super!

gawicks said,

A ReFS is volume is accesible from any OS that supports NTFS.

They have only replaced the LOWER NTFS layer with the new ReFS layer. So the higher level API is compatible with NTFS

Pretty Neat


Nope. That high level API you're speaking of is the one available to programs ; read, write, copy, move, et al.
To support ReFS, an OS must have a driver for it. Win7 (and probably older versions of Windows too) will tell you "there's a valid file system, but I can't read it" as opposed to "it's raw data".

Aethec said,

Nope. That high level API you're speaking of is the one available to programs ; read, write, copy, move, et al.
To support ReFS, an OS must have a driver for it. Win7 (and probably older versions of Windows too) will tell you "there's a valid file system, but I can't read it" as opposed to "it's raw data".

The blog post says, "And of course, data stored on ReFS is accessible through the same file access APIs on clients that are used on any operating system that can access today's NTFS volumes."

So if you can read NTFS it sounds to me like you can read ReFS. The difference is that the client version of Win8 won't be able to create it and so on.

GP007 said,
The blog post says, "And of course, data stored on ReFS is accessible through the same file access APIs on clients that are used on any operating system that can access today's NTFS volumes."

So if you can read NTFS it sounds to me like you can read ReFS. The difference is that the client version of Win8 won't be able to create it and so on.

Again, incorrect, if you read the official blog comments, actual softies are posting and they say it will be like early NTFS days where the client OS will tell you the drive is formatted but will not be able to access the data. This is much better than having it show up as RAW in disk management.

dotf said,

Again, incorrect, if you read the official blog comments, actual softies are posting and they say it will be like early NTFS days where the client OS will tell you the drive is formatted but will not be able to access the data. This is much better than having it show up as RAW in disk management.

I dunno about the blog comments, I'm only going off of what the blog post itself said and it talks about keeping compatibility with NTFS and all the 3rd party tools/apps that can work with it can work with ReFS. Later down in the Q&A section they specifically say you can use 3rd party tools to do things that ReFS doesn't do itself much the same way you can for NTFS.

GP007 said,
I dunno about the blog comments, I'm only going off of what the blog post itself said and it talks about keeping compatibility with NTFS and all the 3rd party tools/apps that can work with it can work with ReFS. Later down in the Q&A section they specifically say you can use 3rd party tools to do things that ReFS doesn't do itself much the same way you can for NTFS.

Look at the comments...Matt Garson [MSFT] says that Win7 will not be able to read ReFS.

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!

It's not even OUT yet calm your puny impatient brain down. That's why it's going on SERVER first, it will be DATA sharing FIRST, no need to make it client side, it will be more robust.. but this is like at LEAST 2 years away.. besides who EVER adopts Windows the same day it comes out, hmmm?

Yeah there will be an article on Neowin in 2 years when Windows 8 server is announced release date, and the FIRST thing someone will say is they will WAIT until the bugs are worked out, so that means 3 years.. So what you are crying now?

Marshalus said,
So now we can have both exFAT and ReFS not being recognized by other operating systems? Awesome!

It's not even OUT yet calm your puny impatient brain down. That's why it's going on SERVER first, it will be DATA sharing FIRST, no need to make it client side, it will be more robust.. but this is like at LEAST 2 years away.. besides who EVER adopts Windows the same day it comes out, hmmm?

Yeah there will be an article on Neowin in 2 years when Windows 8 server is announced release date, and the FIRST thing someone will say is they will WAIT until the bugs are worked out, so that means 3 years.. So what you are crying now?

Aethec said,

Look at the comments...Matt Garson [MSFT] says that Win7 will not be able to read ReFS.

well maybe not directly.. but if it's a Windows 8 server, it will work. Just like now We can read Linux servers and MAC servers, but Windows doesn't necessarily need to read the FileSystem, since it's SHARED by a server..

Aethec said,

Look at the comments...Matt Garson [MSFT] says that Win7 will not be able to read ReFS.

well maybe not directly.. but if it's a Windows 8 server, it will work. Just like now We can read Linux servers and MAC servers, but Windows doesn't necessarily need to read the FileSystem, since it's SHARED by a server..

OMg oh no wait.

I just put my tinfoil hat on. Microsoft are going to CONTROL how my data is written to the system. This has vendor lock-in all over it. How will I be able to read my data unless I have an ReFS capable OS......

Recovery tool vendors and the whole disk ecosystem will have to change.
Oh noes.
not good at all.

Companies like Acronis will definitely implement support in their products, how else will they sell us their shiny new 2013 editions?

dotf said,
OMg oh no wait.

I just put my tinfoil hat on. Microsoft are going to CONTROL how my data is written to the system. This has vendor lock-in all over it. How will I be able to read my data unless I have an ReFS capable OS......

Recovery tool vendors and the whole disk ecosystem will have to change.
Oh noes.
not good at all.


What? Are you being sarcastic or serious? How is that any different from NTFS?

Also, it says in the article that they are creating it with a high degree of compatibility, which I would take as meaning that anything that can read NTFS can read ReFS.

Mikeyx11 said,

What? Are you being sarcastic or serious? How is that any different from NTFS?

Also, it says in the article that they are creating it with a high degree of compatibility, which I would take as meaning that anything that can read NTFS can read ReFS.

Indeed. I remember when products didn't support NTFS. Now they do.

dotf said,
OMg oh no wait.

I just put my tinfoil hat on. Microsoft are going to CONTROL how my data is written to the system. This has vendor lock-in all over it. How will I be able to read my data unless I have an ReFS capable OS......

Recovery tool vendors and the whole disk ecosystem will have to change.
Oh noes.
not good at all.

I hadnt heard that from anywhere else. Care to elaborate on that?

Mikeyx11 said,

What? Are you being sarcastic or serious? How is that any different from NTFS?

Also, it says in the article that they are creating it with a high degree of compatibility, which I would take as meaning that anything that can read NTFS can read ReFS.

well you would be incorrect. I am being both sarcastic in my fanaticism and serious with the implications to the industry.

The new filesystem is like a managed proprietary black box with ntfs thrown on top as the access layer.
What this means is that when NTFS access methods fail due to problems supposedly addressed by ReFS, no one outside of Microsoft will know how to actually pull your data from the disk.

If you can't see how that would cause the crazies to wonder what MS are doing with the bits on disk, then I don't know how to clarify.

dotf said,

well you would be incorrect. I am being both sarcastic in my fanaticism and serious with the implications to the industry.

The new filesystem is like a managed proprietary black box with ntfs thrown on top as the access layer.
What this means is that when NTFS access methods fail due to problems supposedly addressed by ReFS, no one outside of Microsoft will know how to actually pull your data from the disk.

If you can't see how that would cause the crazies to wonder what MS are doing with the bits on disk, then I don't know how to clarify.


I'm only incorrect if your assumptions are correct, which I highly doubt.

You're basically saying that only Microsoft products will be able access disks that use ReFS. This would be completely unworkable for many different reasons.

Consider the immense range of devices used to connect to files on Windows PCs and servers, the great number of external drives used on multiple devices and all the software that requires knowledge of how the file system operates in order to function.

If Microsoft ignored this, they'd have a really hard time trying to encourage its use. The "disk ecosystem" will not need to change at all, it will just need to add another file system.

dotf said,
OMg oh no wait.

I just put my tinfoil hat on. Microsoft are going to CONTROL how my data is written to the system. This has vendor lock-in all over it. How will I be able to read my data unless I have an ReFS capable OS......

Recovery tool vendors and the whole disk ecosystem will have to change.
Oh noes.
not good at all.

Um.. ok.. who do you think OWNS NTFS NOW? Mr. Wizard.. NTFS has been perfect for over 20 years.. I *THINK* that qualifies as pretty resilient itself.

Vendors have to change, and..what's your point? You just ranting because you are waiting for your tablet to restart or what..

Don't "internals" books cover that sort of thing? I know with VMS you could get operating system and file system "Internals" books. Does Microsoft not offer similar tomes?

dotf said,

well you would be incorrect. I am being both sarcastic in my fanaticism and serious with the implications to the industry.

The new filesystem is like a managed proprietary black box with ntfs thrown on top as the access layer.
What this means is that when NTFS access methods fail due to problems supposedly addressed by ReFS, no one outside of Microsoft will know how to actually pull your data from the disk.

If you can't see how that would cause the crazies to wonder what MS are doing with the bits on disk, then I don't know how to clarify.

I read the blog post. He says it will debut for Server first, and client later. I for one can't wait until this hits client OS, say SP2 maybe? Or will there be a hidden setting to enable it on the client OS? Time will tell.

Guess my plan of turning my main PC into a server and virtualizing a desktop for my wife may just be the best approach, just to play with the filesystem.

One of the design goals should resonate with every windows user on this site:

•Never take the file system offline. Assume that in the event of corruptions, it is advantageous to isolate the fault while allowing access to the rest of the volume. This is done while salvaging the maximum amount of data possible, all done live.

Nidoking said,
So, is this the same thing as the code-named "Protogon" file system? It sounds interesting, nonetheless.

It's the same thing, like you said, Protogon was the codename for ReFS.

Windows7even said,
Guessing that re stands for recycled..as in NTSC

I take it you never bothered to read the whole news post... it's Resilient File System.

Windows7even said,
Guessing that re stands for recycled..as in NTSC

I also doubt that they include NTSC TV system in ReFS

Windows7even said,
Guessing that re stands for recycled..as in NTSC

Not sure what analogue TV has to do with computer file systems, but ok.

You know, if you read articles, you may not need to "guess" so much.

Windows7even said,
Guessing that re stands for recycled..as in NTSC
It's retards like you why Freedom of Speech has its downsides.
ROFL seriously, could this guy be more ignorant?

Arthax said,
It's retards like you why Freedom of Speech has its downsides.
ROFL seriously, could this guy be more ignorant?

Guess he wont be changing his nick to Windows8even