Server 2025

[jamerson]

Hi guys,
I am curious if any one you had deployed veeam on server 2025.
I want to deploy this to test it and check the new refs speed.
Can I get 12.1 working on 2025?

[Mildur]

Hi Julien

I saw that a member in our community hub have tried it in his lab. Installation worked so far:
https://community.veeam.com/discussion- ... m-b-r-6614

Of course we don‘t support it yet for any Veeam component or as a backup source. Official support from Veeam comes after Windows Server 2025 was made generally available by Microsoft.

Best,
Fabian

[pesos]

Now that 2025 is out we are using it on a file server (for SMB over QUIC).

Any issue using our current win2022-based veeam b&r server to back up win2025 guests (still running on win2022 hosts) that have refs volumes?

[Gostev]

Actually, Server 2025 hasn't been shipped yet. Most likely you're using some pre-release build.

We're waiting for the RTM build to perform comprehensive testing against.

[pesos]

Hi Gostev! Actually the "RTM" (not that that term means the same thing it did years ago these days!) 26100.1742 build has been available for some time now, and was downloaded via Microsoft itself. MAK and KMS keys also have been made available from MS.

[Gostev]

@pesos thing is, we've been constantly receiving Server 2025 builds from Microsoft and the last one 10 days ago was still marked as preview. Notably, the build number was 26304 which makes it a later build than what you claim to be the RTM build.

Could you perhaps share a link to an official announcement from Microsoft that declares build 26100 as the RTM build? Google is not finding any such announcement for me, while Microsoft used to always makes one for Server releases in the past.

[pesos]

my understanding is that 26100.1742 is the release build (same build number that is 24h2 for win11). it is not yet "ga" - but of course these terms bear little resemblance to what they once did with microsoft's loosey goosey way of doing things these days. looking forward to the ga announcement and 12.3 as well!

[pesos]

And it is now "GA"

https://learn.microsoft.com/en-us/windo ... erver-2025

[stanthewizzard]

Using it
Veeam works as long as there is no guest processing application aware processing

BTW
the migration of the windows that serve the RFS share was a huge mess (more thant 4 hours) ending in the RFS share marked as raw (thank to copy process in place no data was lost. But I needed to re format the partition and move back the data > 6h)

[Mildur]

Official support will come with v12.3.

@stanthewizzard
What's an RFS share? I assume you mean a ReFS filesystem. Because RFS seems to be Unix technology.
Please test it again later this year with v12.3 and Windows 2025 GA. Microsoft's pre-GA builds should never be used in production.

Best regards,
Fabian

[stanthewizzard]

Yes right ReFS

[pesos]

For our part we are not planning on putting Veeam itself on 2025, or backing up 2025 hosts, until 12.3 is out. We are however backing up 2022 hosts that have 2025 guests (file servers for smb over quic) using 12.2

[pesos]

In that vein, is 12.3 with win2025 support expected in calendar year 2024?

[Mildur]

Yes

Best,
Fabian

[pesos]

Thank you! That is super helpful with our planning.

[ARosenstand]

Hi all

Any of you, who have experienced the same problem?

Veeam backup of VM running Server 2025, results in error in application-aware, as System guest OS is not supported.

Failed to prepare guest for hot backup. Error: Unable to perform application-aware processing: Unknown Operating System guest OS is not supported
Error: Unable to perform application-aware processing: Unknown Operating System guest OS is not supported

Veeam B&R Server
OS: Server 2022
Veeam B&R 12.2.0.334

Guest OS on the problematic VM:
Server 2025 Standard
24H2 - Build 26100.2314

[Mildur]

Hello Allan,

The error messages you're encountering are related to a Windows Server version that we do not support yet.
Windows Server 2025 will be officially supported with our upcoming release of Veeam Backup & Replication v12.3, which is targeted for release in December 2024.

Best regards,
Fabian