Windows ReFS versions

Windows ReFS versions.en.md

Version number is reported by fsutil fsinfo refsinfo, available on Windows 10 and Windows Server 2016.

ReFS 1.1

• Version of formatted by Windows Server 2012.
• Version 1.1 is used already in Windows Server 8 Beta. I have never seen version 1.0.
• Can use and store alternate data streams, when mount on 8.1/2012 R2 or later.

ReFS 1.2

• Version of formatted by Windows 8.1, Windows 10 v1507 to v1607, Windows Server 2012 R2, and when specified ReFSv1 on Windows Server 2016 or later.
• Cannot use alternate data streams, when mount on 2012.

ReFS 7.2

• Version that can be formatted with Windows 10 Build 9780

ReFS 9.2

• Version that can be formatted with Windows 10 Technical Preview build 9841 to 9860 and Windows Server 2016 TP1 (It's not default). Could not mount in 10 9879 or 2016 TP2 and later.

ReFS 11.2

• Version that can be formatted with Windows 10 Technical Preview build 9879 (It's not default). Could not mount in 9926 and later.

ReFS 12.2

• Version that can be formatted with Windows 10 Technical Preview build 9926 (It's not default). Could not mount in 10041 and later.

ReFS 22.2

• Version that can be formatted with Windows 10 Technical Preview build 10041 to 10049 (It's not default). Could not mount in 10061 and later.

ReFS 2.0

• Version of formatted by Windows Server 2016 TP2/TP3.
• Version that can be formatted with between Windows 10 Technical Preview build 10061 or later and earlier than 10130 (It's not default). Could not mount in Windows 10 Insider Preview build 10130 and later, or Windows Server 2016 TP4 and later.

ReFS v2 Overview
http://www.snia.org/sites/default/files/SDC15_presentations/file_sys/JRTipton_ReFS_v2.pdf
http://www.snia.org/events/storage-developer/presentations15#file_sys

ReFS 3.0

• Version of formatted by Windows Server 2016 TP4/TP5.
• Upgrade to 3.1 when writable mount from Windows Server 2016 RTM.

ReFS 3.1

• Version of formatted by Windows Server 2016.

ReFS 3.2

• Version of formatted by Windows 10 v1703.
• Version that can be formatted with Windows 10 Insider Preview 15002 or later (It's not default at 15002) and Windows Server Insider Preview build 16237.
  • It became the default between after than 15002 and 15019 or earlier.

ReFS 3.3

• Version of formatted by Windows 10 Enterprise v1709 and Windows Server version 1709.
• Version of formatted by Windows 10 Enterprise Insider Preview build 16257 and Windows Server Insider Preview build 16257.
  • Creation ReFS volume ability was removed from Home and Pro at build 16226 and later.

ReFS 3.4

• Version of formatted by Windows 10 Enterprise v1803, Windows Server 2019 and Windows Server version 1803.
• Version of formatted by Windows 10 Enterprise Insider Preview build 17083 and Windows Server Insider Preview build 17079.

ReFS 3.5

• Version of formatted by Windows 10 Enterprise Insider Preview build 19536 and Windows Server Insider Preview build 19551.
• Added hardlink support if fresh formatted volume.
  • Can't use hardlink if upgraded from previous version.
• Upgrade to 3.6 when writable mount from Windows 10 Insider Preview build 21292.

ReFS 3.6

• Version of formatted by Windows 10 Enterprise Insider Preview build 21292 and Windows Server Insider Preview build 20282.
• Upgrade to 3.7 when writable mount from Windows 10 Insider Preview build 21313.

ReFS 3.7

• Version of formatted by Windows 11 Enterprise v21H2 and Windows Server 2022.
• Version of formatted by Windows 10 Enterprise Insider Preview build 21313 and Windows Server Insider Preview build 20303.

ReFS 3.9

• Version of formatted by Windows 11 Enterprise v22H2.
• Version of formatted by Windows 11 Enterprise Insider Preview build 22598 and Windows Server Insider Preview build 25099.
• Added post process compression with LZ4 & ZSTD, transparent decompression.

ReFS 3.10

• Version formatted by Windows 11 Enterprise Insider build 25324 through 25997 and builds 26010

ReFS 3.12

• Version formatted by Windows 11 Enterprise Insider build 26002. Build 26010 reverts back to 3.10

Mountability

ReFS\Windows	2012	8.1/2012 R2	10 v1507	2016	10 v1703	10 v1709	10 v1803/2019	11 v21H2/2022	11 v22H2	Canary Channel
1.1	Yes	Yes1	Yes1	Yes1	Yes1	Yes1	Yes1	Yes1	Yes1
1.2	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
3.1	No	No	No	Yes	Yes2	Yes3	Yes4	Yes56	Yes76
3.2			No	No	Yes	Yes3	Yes4	Yes56	Yes76
3.3				No	No	Yes	Yes4	Yes56	Yes76
3.4						No	Yes	Yes56	Yes76
3.7							No	Yes	Yes8
3.9								No	Yes
3.10								No	No	Yes9
3.12								No	No	Yes

License: CC BY

Footnotes

1. "Volume "?:" was mounted in an older version of Windows. Some features may be lost." was recorded to event log when writable mount. I don't know what's been lost. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

2. Upgrade to 3.2 when writable mount. ↩

3. Upgrade to 3.3 when writable mount. ↩ ↩²

4. Upgrade to 3.4 when writable mount. ↩ ↩² ↩³

5. Upgrade to 3.7 when writable mount. ↩ ↩² ↩³ ↩⁴

6. Can't use hardlink. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

7. Upgrade to 3.9 when writable mount. Can't mount read-only. ↩ ↩² ↩³ ↩⁴

8. Upgrade to 3.9 when writable mount. ↩

9. Builds 25324 to 25997 ↩

^ thanks for the service! I will talk to MSFT if they can reveal more on the changes made in the respective versions

Hi there it this is explanation why ReFS now supports boot of the OS

Perhaps this is not the place to ask, do let me know and forgive me if I clutter the flow with my Q.
I parse ReFS myself and have (from all my testing in the past) a decent working version. 1.x, 2.x and 3.x. But .. I neglected ReFS a bit and I haven't looked at it for years. My last tests were on v 3.7 and it worked fine. Yesterday, when I plugged in an old HDD (not sure what version of ReFS) my W11 system crashed horribly. It was a trigger to start looking into ReFS again. I formatted a partition with ReFS using an up to date W11 system and it appears to be version 3.10. But ... I can't seem to find the root anymore. My code appears to be broken for this version of ReFS. Frankly I did not expect data structures to change in a major version range, and I'm completely in the dark Are there people here who look at the data structures at a lower level ? I need a clue .. what changed between 3.7 and 3.10 that could explain decent working code to stop working entirely.

Greetings @CyberGonzo I read your question twice but still require more information to provide an answer.

Not maintainer. I just can assume but I believe it would be good to move a technical question from this gist to techcommunity.microsoft.com, but that is on @XenoPanther to decide.
If not appropriate., I would like to encourage you to repost on techcommunity
Windows Server for IT Pro
or
Windows and provide a link to the question?

May I ask you to elaborate on your question:

"I can't seem to find the root anymore. My code appears to be broken for this version of ReFS"

Q1: What do you mean by "cannot find the root? You mean the drive become inaccessible, appearing as RAW in File Explorer

Issue:
you attached an external drive formatted with ReFS to your Windows 11 Enterprise
assuming as Windows 11 pro cannot format ReFS anymore.
your PC crashed.
you choose to reformat the drive with Windows 11 Enterprise. The drive was then healthy and working.

Q2: Are you looking into debugging the crash at all or is it wasted time?

"my code appears to be broken for this version of ReFS."

Q3: Could you tell more about your your code, at best posting it on techcommunity, too. If you don't want to post it publicly you can provide me a DM.
I will treat confidential when required.

What would be needed as a bare minimum is a synopsis of your code and the parsing process you describe, the use case and goal.
You can enter it in Edge > Copilot GPT-4 and "write a synopsis" and enter the code.
In addition, what does fail with your code with ReFS 3.10 (error code, expected behaviour, actual behaviour)

Looking forward to hearing from you!

Thank you @Karl-WE, for getting back to me. I admit the question is rather superficial and mainly opportunistic as I was probably hoping for a "yes, they added this or removed that or .. " which could potentially lead me to the culprit. The question was born out of late night desperation and frustration before I signed off. Meanwhile I am knee deep in the code again, trying to figure out if it's really something new or a corner case or ..

Thanks for the links. When I'm totally out of ideas after looking into the code, I might post there, but do people comment there on the deeper mechanics (data structures etc) ?

Q1: What do you mean by "cannot find the root? You mean the drive become inaccessible, appearing as RAW in File Explorer

I meant my software can't find the root anymore. Explorer finds it just fine, the issue is in my software.

Q2: Are you looking into debugging the crash at all or is it wasted time?

I have several ReFS partitions I now find that crash my W11 immediately. Scary how the W11 driver is handling ReFS it doesn't support (anymore - I assume). Only the Windows file system driver team can fix this I'm afraid / I assume.

Q3: Could you tell more about your your code, at best posting it on techcommunity, too.

I can't share the code, but my software, that contains the code, is IsoBuster. Add .com and you'll find it online ;)

What I have found so far is that problems start with the B-Tree parsing of the (what I call $CT) container files.
I identified an issue yesterday, which I will fix today, but it's not the whole story. There's more that is working differently, in particular the From Node, To Node type headers seem not to work as expected .. but we're really getting to the low level mechanics now.

I should add that I have a working version again. Sorry if I wasted anybody's time. It was a combination of an untested situation (which was not handled well in the code) and unexpected data in one of the headers. I fixed the former and now work around the latter.

HI @CyberGonzo thanks for the reply and good to know you have addressed it somehow.

Do I understand correctly you are the maintainer of the said software?

I have several ReFS partitions that crash my W11 immediately. Scary how the W11 driver is managing ReFS it doesn't support (anymore - I assume). Only the Windows file system driver team can fix this I'm afraid / I assume.

It is hard to provide any support if you are a software developer I can try to connect you with capable folks that might want to investigate it once we have data and repro steps. Be prepared to raise a Microsoft support ticket, too, so we can keep it formal.
Without a SR and more information, it is hard to understand why you experience the crashes, this is not usually the case I am collaborating with ReFS on W11 every day. Thus, my interest into your pain in the first place.

Hi @Karl-WE, sure if you know of people who are interested in this, I'm certainly willing to provide more information, though I have only W11 machines at the moment and W11 crashes the moment Windows accesses the ReFS partition.
I am the developer of said software, yes.

@CyberGonzo, As far as I know there is no relatively well-developed structure in the open source projects, and the unsound/refsprogs project is currently a little bit of resolution to the file\folder name of the project.

Thank you @nblog, but I was able to fix the issue and all is working well again. Thanks for the open source suggestion but upon reading its description I think my implementation is more advanced already anyway.

As a test I wanted to see if I could produce refsutil output on a healthy refs volume, for the sake of investigation and possibly parsing.
I am baffled by what I got:

C:\Windows\System32>Refsutil salvage -QS w: m:\refstest -x -v
Microsoft ReFS Salvage [Version 10.0.11070]
Copyright (c) 2015 Microsoft Corp.

Local time: 4/5/2024 10:29:49

Option(s) specified: -v -x

ReFS version: 3.10
Error: The volume is an unsupported ReFS version. This utility supports versions up to 3.9. Volume is 3.10.
Error: Command failed.
Error: The volume does not contain a recognized file system. Please make sure that all required file system drivers are loaded and that the volume is not corrupt.

How is it possible that on my Windows 11 Pro version: 10.0.22631 Build: 22631 I can format a partition with ReFS (default settings) which then turns out to be version 3.10, but the refsutil version that is present on that same system cannot handle the (default) refs version !? That is mind boggling.

Any idea how I can update refsutil to v3.10 without messing my system up ?

Yes, it is mindbloggling and I catched that some time ago. https://techcommunity.microsoft.com/t5/windows-server-insiders/b25951-refs-3-10-volume-became-raw-refsutil-not-compatible-with/m-p/3947990/highlight/true#M3139
So do understand your crashes, I would kindly ask you to open a SR with Microsoft Support (e.g Visual Studio Enterprise, or you could use Azure Dev/Test Support and using an Azure VM.
As soon you have the Ticket number come back to me and I will help you to manage to bring it to the ReFS people. They signalled interest into this. TYVM. Is this fine with you?

Yes, it is mindbloggling and I catched that some time ago. https://techcommunity.microsoft.com/t5/windows-server-insiders/b25951-refs-3-10-volume-became-raw-refsutil-not-compatible-with/m-p/3947990/highlight/true#M3139
So do understand your crashes, I would kindly ask you to open a SR with Microsoft Support you have certainly access to support.
As soon you have the Ticket number come back to me and I will help you to manage to bring it to the ReFS people. They signalled.
If you can repro the crash on connection issue in a preview version of Windows 11, we might not require a SR.
I had this issue once but only for older versions of ReFS.
try to find out the ReFS version of the attached disk. It should survive a powershell > fsutil fsinfo refsinfo dl: command, hopefully

Hi @Karl-WE, I have never reported an issue with MS before and the methods you describe are all Latin to me.
The problem with my HDD and Images is that the moment I attach them to the system, the system crashes.
A while back I cloned an older ReFS version from an image to a partition (my software does that) and the moment Windows accessed the partition it blue-screen-crashed and would simply not boot anymore. I fixed it by booting the system with an older W10 boot DVD and by overwriting the partition with rubbish (using my software again).
I suppose I could boot the system again using that W10 DVD.

Ok Gonzo, let us proceed offline. I got your DM!

I booted in W10. I'm starting to feel confident W11 crashes because of ReFS 2.0. Turns out the HDD has 4 ReFS partitions. versions 1.2, 2.0 and 3.4. W10 mounted 1.2 and 3.4 correctly but failed to see 2.0. I think W11 takes it a step further and crashes on ReFS v 2.0.

@CyberGonzo it is possible to try to analyze the DUMP file as ReFS 3.x (refs.sys) and ReFS 1-2 (refsv1.sys) are two different drivers,

It says both Could not read faulting driver name and
MODULE_NAME: ReFS IMAGE_NAME: ReFS.SYS FAILURE_BUCKET_ID: AV_R_INVALID_ReFS!CreateUnicodeStringDirectorKey
The latter suggesting the ReFS 3.x driver then

Just FYI and to complete my earlier findings. I cloned a small ReFS v 3.2 image to a HDD and W11 crashed immediately after mounting the disk. So it's not v 2.0 as I thought. It's also v 3.x. (PS. I used the publicly available image refs-v3_2.E01 found here: https://data.mendeley.com/datasets/9d7p6mbhpz/1

Supports Encrypted File System is now available in the build 24H2 release preview channel with ReFS v3.14

How do I start the compression process?
I successfully ran refsutil compression /c /f ZSTD /e 22 e:
But the compression statistic refsutil compression /q e: shows me only zeros.
Windows Server 2025 10.0.26100.560

If Windows is installed on an ReFS partition, it may not pass OOBE. This issue has been present since at least build 26080, and it also exists in builds 26095, 26100 (.1, .560), and 26200. I haven’t tested this on more version, but I believe the problem persists in all versions from the past six months. bypassnro is not the cause of the failure, but it results in different outcomes. Specifically, users may experience the following symptoms:

UI freezing when filling out security questions.
‘OOBELOCAL’ error after completing security questions.
Spinning indefinitely after logging in with a Microsoft account.

Initially, the issue occurred on my Surface Book 3. However, today it happened on an ASUS laptop using the unmodified Microsoft released 26100.560 image. Symptoms disappear after turning off SecureBoot on Asus laptop.

Therefore, even though Microsoft has officially announced that Windows Server supports using ReFS as the boot file system, there are still some compatibility issues.

Build 27686:

PS C:\Users\Bizwen> fsutil fsinfo refsinfo D:
REFS Volume Serial Number :                0xUUUUUUUUUUUUUUUU
REFS Volume Version :                      3.14
REFS Driver Maximum Supported Version :    3.15
Number Sectors :                           0xUUUUUUUUUUUUUUUU
Total Clusters :                           0xUUUUUUUUUUUUUUUU
Free Clusters  :                           0xUUUUUUUUUUUUUUUU
Total Reserved :                           0xUUUUUUUUUUUUUUUU
Bytes Per Sector  :                        512
Bytes Per Physical Sector :                4096
Bytes Per Cluster :                        4096
Fast Tier Data Fill Percentage :           0.0%
Slow Tier Data Fill Percentage :           0.0%
Fast Tier to Slow Tier Rate (Clusters/s) : 0
Metadata Checksum Type :                   CHECKSUM_TYPE_CRC64
Data Checksum Type :                       CHECKSUM_TYPE_NONE

Unlike previous versions, ReFS 3.14 does not automatically upgrade to ReFS 3.15.

As of Build 27686, refsutil salvage still does not work. refsutil salvage only supports ReFS 3.9 and earlier. Does this mean that the tool is deprecated and not maintained?

Hi everyone, thanks for keeping this gist alive and updated.
Had the same question as you @YexuanXiao stated here

I have asked Microsoft and received the following answers to share:

Is it planned to update ReFSutil to salvage 3.9+ version?
Yes, we are working on updating refsutil salvage to handle the latest format. The updates have to be backported to the appropriate release
pipelines, which takes time, please be patient.

Is the reported behaviour intended that ReFS will not autoupgrade from 3.14 to 3.15?
3.14 is Ge/WS2025 ReFS version. 3.15 is for future, there’s no way to get to 3.15 publicly.

Hope this helps!

Hi everyone, thanks for keeping this gist alive and updated.
Had the same question as you @YexuanXiao stated here
I have asked around and received the following answers I may share:

Is it planned to update ReFSutil to salvage 3.9+ version?
Yes, we are working on updating refsutil salvage to handle the latest format. The updates have to be backported to the appropriate release
pipelines, which takes time, please be patient.

Is the reported behaviour intended that ReFS will not autoupgrade from 3.14 to 3.15?
3.14 is Ge/WS2025 ReFS version. 3.15 is for future, there’s no way to get to 3.15 publicly.

Build 27723:
C:\Users\ThinkPad>sudo fsutil fsinfo refsinfo e:
REFS Volume Serial Number : 0x847623a07623924a
REFS Volume Version : 3.14
REFS Driver Maximum Supported Version : 3.15
Number Sectors : 0x0000000003fe0000
Total Clusters : 0x00000000007fc000
Free Clusters : 0x00000000007a2ed8
Total Reserved : 0x0000000000025048
Bytes Per Sector : 512
Bytes Per Physical Sector : 4096
Bytes Per Cluster : 4096
Fast Tier Data Fill Percentage : 0.0%
Slow Tier Data Fill Percentage : 0.0%
Fast Tier to Slow Tier Rate (Clusters/s) : 0
Metadata Checksum Type : CHECKSUM_TYPE_CRC64
Data Checksum Type : CHECKSUM_TYPE_NONE
ReFS v3.15 is still not available now.

Have filed a PR to address that "additional information" will link to this gist, instead of the abandoned one. MicrosoftDocs/windowsserverdocs#7960