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The Samba team at SerNet has reached another major milestone in the STA-funded development project: SMB Direct (RDMA) support is now taking shape in the Linux kernel. This marks a new stage for Samba – bringing high-speed, low-latency data transfer into the open-source world. With Remote Direct Memory Access (RDMA), data moves directly between client and server network adapters, bypassing the CPU and reducing latency. The result: enterprise-grade performance, available in an open, community-driven stack.

159 patches later

Developing SMB Direct required deep kernel integration. Over 159 patches, the Samba team unified existing SMB Direct components for both client and server, which paves the way toward a shared socket layer that can be exported to user space via socket API and then used by applications like Samba. This foundation enables future work on full SMB Direct support in smbd and smbclient, as well as automated testing and performance validation.

Several commits have already been merged into the main Linux kernel, with further work under active review: a milestone made possible through collaboration between Samba developers, kernel maintainers, and the wider Linux community.

Open performance, sovereign infrastructure 

SMB Direct is more than a technical upgrade. It’s a step toward digital sovereignty through performance and openness. By making advanced data-transfer capabilities available as free software, Samba enables secure, scalable file services without proprietary dependencies. The Sovereign Tech Agency (STA) supports this work as part of its mission to strengthen open digital infrastructure and Europe’s technological resilience.

With STA funding, Samba can focus on the kind of long-term, architectural development that benefits everyone from enterprises to public institutions.

Learn more about the full STA-funded Samba project and all milestones: https://samba.plus/stf-project

The Samba team at SerNet has completed another important milestone in the STF-funded development of the open-source Samba software: Milestone 3.3 focuses on improved integration with Linux desktop environments and is part of the broader SMB3 UNIX Extensions milestone group.

The goal of this work is to make Samba a more natural and consistent part of Unix-like operating systems. To achieve this, the team has extended libsmbclient, the client-side library used by major desktop environments such as GNOME and KDE to access SMB file shares. By enabling support for SMB3 POSIX extensions in this library, Samba now offers better handling of symbolic links, permissions, and metadata making file access on the desktop feel more like using a local Unix filesystem. The team also put in the work to provide the code needed for GNOME to enable the SMB3 Unix Extensions.

This milestone builds on earlier work within the SMB3 UNIX Extensions group: Milestone 3.1 focused on the server-side implementation of POSIX-compatible features. With Milestone 3.3, these improvements are now reaching Linux desktop environments and deliver the benefits of SMB3 UNIX Extensions directly to end users.

The achievement is part of the ongoing effort to enhance Samba’s security, scalability, and integration. The goal is to ensure that Samba remains a powerful, interoperable solution for sovereign IT environments and is funded by the Sovereign Tech Agency.

Patched SAMBA+ packages are now available to address the Netlogon protocol change introduced by Microsoft’s latest updates to Windows Active Directory Domain Controllers.

Following our initial announcement, the updates from Microsoft introduce a critical change that may impact Samba installations in certain configurations. To ensure compatibility, fixed SAMBA+ packages have been released for the following branches:

• SAMBA+ 4.21
• SAMBA+ 4.22

If you are still using an older release branch, we strongly recommend migrating to 4.21 or 4.22 to receive the necessary fix.

Who needs the update?
You only need to install the patched packages if:

• Samba is configured as a member server, and
• you're using the idmap backend ad

Other Samba setups are not affected.

For full technical details, please refer to the official Samba release notes:
Samba 4.21.7 Release Notes
Samba 4.22.3 Release Notes

If you need help updating your installation or have questions about compatibility, feel free to contact us – we’re happy to support you.

Debian 13 "Trixie" has not yet been officially released, but SAMBA+ packages are already available. Starting with version 4.22, SerNet provides prebuilt SAMBA+ packages for the upcoming Debian release. Supported architectures are amd64 and arm64, in line with Debian’s decision to discontinue 32-bit variants.

By offering early access to these packages, the SAMBA+ team ensures that administrators and IT professionals can plan and test ahead. This proactive approach supports smooth transitions and secure operations in demanding environments.

Built from the official Samba source code, SAMBA+ packages offer more than just compatibility. They include extended testing, continuous security updates and the option for enterprise-grade support directly from SerNet.

All supported platforms, including the new Trixie packages, are listed in our overview. Technical setup instructions and repository details are available in the How-to Section. 

For questions, feel free to contact us at sales@remove-this.sernet.com

(Last Update: July 8)

Please note: Updated packages are available

On July 8, Microsoft will release an important security update for Active Directory Domain Controllers for Windows Server versions prior to 2025.

This update modifies the Microsoft RPC Netlogon protocol to improve security by tightening access checks for a set of RPC requests. Samba running as domain members in these environments will be impacted by this change if a specific configuration is used. See below for details on the affected configurations.

Windows Server version 2025 is already equipped with these specific security hardenings. Microsoft plans to deploy them to all supported Windows Server versions down to Windows Server 2008. 

Who is affected?
Samba installations that act as member servers in Windows AD domains will be affected if they are configured to use the 'ad' idmapping backend. Samba servers that do not use this configuration will not be affected by the change – at least according to our current knowledge and understanding – and no further action is required.

However, current versions of Samba with the affected configuration will no longer function correctly once the Microsoft update has been applied. Users will not be able to connect to the SMB service provided by Samba for any domain that uses the ‘ad’ idmapping backend.

What is SerNet doing?
The SAMBA+ team at SerNet, along with other members of the international Samba team, has been collaborating with Microsoft. Changes to Samba are currently being developed and tested to ensure full compatibility between Samba and Microsoft products. The Samba team aims to release updated packages on Monday evening (UTC+2).

Updated SAMBA+ packages, which will restore full compatibility, are planned to be made available before Microsoft's rollout.

What you should do:

• Check your configuration if you’re running Samba in a Windows AD environment.
• Watch out for new SAMBA+ package updates early next week (starting July 7th) .
• Apply the update before Microsoft’s rolls out the patch.

All SAMBA+ updates are included in active subscriptions.

If you do not yet have a subscription, visit the SAMBA+ shop (EUR) or SAMBA+ shop (USD) for access.

For any questions or individual support, feel free to contact us directly – our team is here to help.