ReFS volume corrupted after terminating iSCSI connection from Windows iSCSI Initiator GUI

Question

I recently lost a ReFS volume on a NAS (QNAP TS-832PXU), connected to a Windows 2019 server through iSCSI. The NAS is used only for backups and is only connected to that server. Suddenly, after a restart of the Windows server, the volume showed up as RAW.

Some hours earlier in the morning, for maintenance activity on the QNAP (network settings rearrangement), the iSCSI connection was terminated from Windows through the iSCSI Initiator mmc, without preventively putting offline the volume from Windows Disk Management (diskmgmt.msc). However, there were not any running activities on the volume at that time. Hours later, eventlog showed the attached relevant events (and several others identical).

We then snapshot reverted the LUN to a functional state and volume came back up correctly mounted.

We already contacted the QNAP support to ask them if they are aware of any issue related to the use of ReFS volumes on their NAS. They say that it is unrelevant for the QNAP the filesystem used on the presented LUNs.

So, kindly can you tell me your opinion on this catastrophic event, why did this happen?

Thank you,
Francesco

Answer 1

Hey,

Have you installed any updates on your Windows Server? There was an issue with one of the updates:
https://techcommunity.microsoft.com/t5/windows-server-for-it-pro/refs-volume-appears-raw-version-doesn-t-match-expected-value/m-p/3058652

In addition, check with QNAP if ReFS is supported. Might help:
https://www.veeam.com/kb2792

As another option, you can try using StarWind VSAN with ReFS. VSAN's iSCSI target was tested to work with ReFS.

https://www.starwindsoftware.com/starwind-virtual-san

Cheers,    
Alex Bykovskyi    
StarWind Software    
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Answer 2

@Alex Bykovskyi thanks for your inputs.

Have you installed any updates on your Windows Server? There was an issue with one of the updates:

Yes. When the issue occured Windows 2019 was already updated with latest updates, August '23 updates at the time.

In addition, check with QNAP if ReFS is supported.

I have a ticket currenly in progress with QNAP. I explicitly asked to confirm that ReFS is fully supported on my model.

As another option, you can try using StarWind VSAN with ReFS. VSAN's iSCSI target was tested to work with ReFS.

Not an option for us. We already have an HPE Apollo as a primary immutable repository. QNAP is just a NAS used for backup copies.

From my readings on this matter I begin to think that ReFS is not that mature, not in terms of flexibility. It has many constraints. Basically it seems that it works very well with direct attached storage/internal storage, with controllers and battery backed write caches.

Moreover I am deploying a new Exchange Server 2019 with ReFS for database and logs (esxi 7 simple VM with normal vmdk files on a vmfs datastore), as recommended in MS documentation. I hope to not have nasty surprises in the future for this.