Windows Server 2019 refs disk not accessible

Question

Hi,

I'm using a Windows 2019 Server in prod with refs disk.

After booting on the same server with Window Server 2022 for test, the refs disk are not accessible anymore on Windows Server 2019. The disk are indicated as RAW on the disk manager.

How to resolve this issue ?

Best regards

Tahar

Answer 1

Hello,

Windows Server 2022 uses ReFS version 3.7, which is not fully backward compatible with the version used by Windows Server 20191. This is why your ReFS disk appears as RAW when you try to access it on Windows Server 2019.

Here are a few steps you can take to resolve this issue:

Use Windows Server 2022: If possible, continue using Windows Server 2022 to access the ReFS disk. This will ensure compatibility with the ReFS version.

Data Backup and Migration: If you need to revert to Windows Server 2019, you can back up the data from the ReFS disk while it's accessible on Windows Server 2022. Then, reformat the disk with the ReFS version supported by Windows Server 2019 and restore the data.

Have a nice day.

Best Regards,

Hania Lian

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Answer 2

Hello,

Thanks for your answer.

It's Windows Server 2019 Datacenter edition that is installed on the machine which serve as Hyper-V Replica. Migrating to 2022 or 2025 is really not cheap.

I solved my problem by doing the following:

• Starting Windows Server 2022
• Copy to another disk (I used Robocopy)
• Format the ReFS disks to NTFS
• Move the previously copied files back to their original locations
• Starting Windows Server 2019
• Resume Hyper-V virtual machine replications...

It was tedious.

I was hoping there would be an easier solution by downgrading to the supported version of ReFS in Windows Server 2019. Especially since the upgrade was done automatically when running Windows Server 2022. That was a shame!

Best regards

Tahar