ReFS volume inaccessible after update from Windows 10 22H2 to Windows 11 23H2

Hi all, 

When using ReFS for internal drives, please consider to disable ReFS upgrade before upgrading to Windows 11 23H2 or 24H2.

Important: Do not use ReFS for Windows OS drives or external / removeable drives.

How-to temporary disable ReFS upgrades:

It needs to be set before connecting an "online / mounted" volume to a newer OS. 

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
"RefsDisableVolumeUpgrade"=dword:00000001

Effect of this setting:

Mounting a ReFS volume to a (newer) OS, with this registry key set - for this OS instance - will prevent upgrading to the lastest ReFS metadata version. 

If you are using multi-boot, it needs to be the same for all OSes

Reasons:

On this thread, but also on GitHub as well as the previous gist, there are different reports about the issue. 

There's a risk of duplicate reports, however there are also singular reports for "Windows Server 2025 / Azure Local 23H2" based issues. Reports here and on gist focusing on Windows Client OS.

Generally, I sense a number of issue reports with the upgrade. These either take longer than expected or ReFS upgrade worked but files still cannot be read / accessed correctly. 

Setting up the registry key will not upgrade your ReFS. Downgrade or rollback to previous Windows OS version are possible. 

Next steps:

We would require support requests and reproducible conditions, quite hard as one needs to simulate quite some fair amount of files and folders. 

With empty or near empty small drives, I doubt this is going to be reproducible. 

Possible issues:

Disable ReFS upgrades gives peace of mind at the moment. Yet can cause outlier configs if people forget to disable the setting. 

Means: ReFS version and OS version no longer match. 

Reverting the change:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem]
"RefsDisableVolumeUpgrade"=dword:00000000

Please mind, that ReFS upgrade will cause read and writes during the upgrade time. There's no progress visible. The upgrade takes time based on media type, like HDD vs NVMe, size, and number of TB of files. 

Be mindful: There is no command to initiate the ReFS upgrade, monitor or revert (downgrade) ReFS. Mind when using Spaces Spaces, do not upgrade the Pool if you want to roll back to an older release or need to access the Pool from different OS Versions (multi-boot). 

Recommendation for reporting issues:

Before upgrading 

Include the Windows version, build and Edition of the OS before upgrading to 23H2 /24H2. Find these with get-computerinfo or PC-Infos in settings app

Include information or Screenshots from Get-Volume 

Include Information about ReFS version

fsutil fsinfo refsinfo DriveLetter:

Windows 11 22H2, 23H2 and 24H2 do not share the same versions of ReFS. 

Do you use Windows default storage drivers? 

What's the amount of files, folders and TB of data? 

Do you use AMD or Intel RAID / VMD? 

Do you use Storage Spaces? 

Post upgrade

Include the same information. 

If ReFS upgrade is not disabled, please let it work in the background to upgrade. Avoid reboots and other changes, storage driver updates etc. 

Experienced the exact same issue. ReFS volume is in a storage space and is ReFS version 3.4. Update to Windows 11 23H2 rendered the volume inaccessible. I rolled back to Windows 10 22H2, which restored access to the volume.

I then downloaded the Windows 11 24H2 iso and initiated the upgrade, from a usb drive formatted with Rufus, from within windows. After the upgrade the volume is visible, files and folders can be enumerated. However, all files are missing security info and cannot be accessed.

I tried simply replacing all files security info with inherited permissions from the drive root, which did display accurate security information, but I received an error for each file stating that it was not accessible. I canceled the operation. Now what to do?

Fortunately I have enough free space on my storage space array to carve out a new ReFS volume of the same size that is no longer accessible. Also fortunately, everything on the inaccessible ReFS volume is backed up on external SSDs. So, I simply restore everything from backups, deleted the original ReFS volume, and assigned the new volume to the previous volume's drive letter 🙂 and all is well.

Sharing my experience because there are obviously still issues with ReFS compatibility when moving to newer versions of Windows, even the latest release. The only way to ensure your data is safe is to have multiple copies. The positive part of my "solution" is that the new ReFS volume is version 3.14. While less compatible with previous versions of Windows, I'm hoping the kinks are worked out with these later versions of the file system and I won't have to go through this same exercise in the future.

Thanks for this post. I hit this issue after doing an in-place upgrade of Windows 10 23H2 Enterprise to Windows 11 24H2 Enterprise. A secondary disk (not the OS disk) was formatted as ReFS. In fact, all attempts to upgrade to 11 23H2 failed; even booting from the ISO caused a blue screen--I wonder if the ReFS volume was the issue. At least the 24H2 upgrade worked, but then I had an unreadable volume.

To get access to the data, I booted from a Windows 10 installer ISO, got to a command prompt, and used RoboCopy to copy data from the ReFS disk to an NTFS disk. First use diskpart with "list vol" to get the drive letters as assigned in the recovery environment. Then, for example, to copy a E:\VMExport folder to F:\DriveE\VMExport:

robocopy "E:\VMExport" "F:\DriveE\VMExport" /E /B /XJ /DCOPY:T /COPY:DAT /R:0 /W:0

The params are described here;

https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/robocopy

We installed a Western Digital NVME Black in a Windows 10 Enterprise workstation with the latest build. The format of the drive is ReFS. When we upgraded the OS to the Windows 11 Enterprise, this drive was not recognized. This drive works well in the Windows 10 Enterprise environment and it is recognized in the BIOS. WD claims no one ever has reported such an issue as mine. What is the solution to this problem?

Hey MikeLabatt, 
I am facing the exact same issue. 
Updated to Windows 11 because of the annoying popups. 
Going back to Windows 10 is not a solution. I can´t read the ReFs File system any more. 

Running  ReFSUtil Salvage -QS I: C:\refsutil  get´s no errors as far as a can see. 
Versión de ReFS: 3.4

Using https://www.reclaime.com/ I can see that all the files are there. 

I have 3 x 4TB drives in parity mode. No hardware problem found.
Now I am waiting for a new drive to copy all my data. 
This is not what I was expecting from a "Resilient " File System.

No solution found yet. Let me know if you get some success.