Moving iSCSI-connected ReFS repository to new Veeam Server

[JosvwHLT]

What is the best approach and what do I need to be aware of when moving a ReFS repository to a new Veeam Server (and not ending up with a RAW volume)? Would it just work when both ReFS versions are the same? We are not using backup copy jobs to create backup copies on a 2nd. location but instead replicate the servers to this 2nd. location, so they are always available in case we need them (for whatever reason). Not our complete server park is replicated, only the core servers. The rest of the servers remain on the backup ReFS repository. In case I lose my Veeam Server and need to rebuild a new server can I just move and connect that existing ReFS repository to the new server? The Veeam Server and the iSCSI-connected NAS (with the ReFS repository) are both located in the 2nd.(DSR) location.

[Mildur]

Hi

You should be able to reconnect the iSCSI LUN to a server with a higher windows version and patch level as the original one. But this question is better asked in a microsoft product forum. I know that it works, but I can not guarantee it. You could test it with a second LUN which contains some example data.

One thing to add:
- Consider having an airgapped or immutable backup copy.
As far as I understand your environment, all your copies of the core servers are reachable from the backup server. When I have access to the backup server, I can delete all replicas, I can delete all backup files and I can export the credentials for the source host and delete all vms there.
A backup copy job to a usb disk, a tape job or using object storage with immutability would be really helpful against malicious attacks. This can be attacks from outside or even from an insider (an employee who wants to deal damage, can happen).

Thanks
Fabian

[gmajestix]

From operating system perspective you unmount the volume and present it to the new server. However when using different Windows Server version for example the old one is 2016 and a new one 2019 or 2022 the ReFS version will be automatically updated to the new version. In case you want to go back to the old server the volume will be seen as RAW. Dont worry no data is lost. Speaking from experience . Its just that older version of Windows server cannot read the newer version of ReFS. Keep that in mind when moving LUNs with ReFS between older and newer versions of Windows Server.

[JosvwHLT]

Thanks Mildur, gmajestix for replying with your very helpful replies. Took note of the comments from Mildur.

[marog0]

Thank you, man. You saved me from a panic attack. The customer had the disk on a WS2012R2 by iSCSI and Pass-through on the Veeam virtual machine with WS2016. When migrating to a new WS2022 host, in the attempt to present the disk with the same strategy, when connecting the volume via iSCSI on the 2022, the OS changed the version of ReFS! When going back always RAW format....
In the end I had to remove all iSCSI connections prior to the WS2012 and 2016, and connect only without Pass-through to the 2022, put the disk Online and scratch that, the folder is visible....
What a terrible time I had.