TrueNAS 27 RC.1 Arrives With Linux 6.18, Renamed From 26

iXsystems has released TrueNAS 27 RC.1, the next major version of its Linux-based storage OS. It was released on October 5, 2026. The stable version is expected to be available as TrueNAS 27.0 in December 2026. Reporting by Michael Larabel of Phoronix noted that it adopts Linux 6.18 LTS and OpenZFS 2.4 as its foundation.

TrueNAS 27 RC.1 released today in working toward the next major release of this Linux-based storage/NAS operating system from iXsystems.

This article is based on Phoronix (All Rights Reserved), relying on fair quotation under Article 32 of the Japanese Copyright Act. This release candidate is positioned as a stage for validating feature additions and foundation updates together. Its pillars are the renaming, kernel updates, and enhanced search and sharing. The contents directly affect storage infrastructure operations at enterprises and research institutions.

Why the Version Number Changed From 26 to 27

Initially, this version was developed as TrueNAS 26. The developers ultimately changed the version number to TrueNAS 27. The decision reflects the expectation that most users will actually deploy it in 2027. It reflects the year of peak adoption rather than the year of initial release.

Version numbers affect deployment plans and procurement documents. For deployments spanning fiscal years, the notation is tied to maintenance contracts and asset management. After the stable release in December 2026, the peak of deployments is expected to come the following year. This can be seen as an alignment with that reality.

iXsystems explained the background in an article on TrueNAS.com. The aim is to finalize the name at the release candidate stage and reduce confusion in documentation and displays. Renaming late in development is unusual, but disruption in production environments is seen as small. This is because evaluation and testing records can be unified under the 27 name.

Linux 6.18 and OpenZFS 2.4 Foundation

The core of TrueNAS 27 is Linux 6.18 LTS. By adopting the long-term support kernel, it ensures stability over the maintenance period. At the same time, it incorporates OpenZFS 2.4, updating the storage system. These two updates form the basis for performance and hardware support.

Updating the Linux kernel directly expands hardware support. It advances support for new controllers and network devices. It also includes power management and processing efficiency improvements. For a storage-dedicated OS, short downtime is critical.

Kernel trends are common to other distributions. New Zenwalk Release Features Linux 7.1 and Xfce 4.20 showed adoption of a new kernel in a lightweight desktop environment. Nova Lake S Gets 7 GPU IDs on Linux 7.3 showed the process of supporting new processors. Nouveau Merges Blackwell Display Fixes Into Linux 7.3-rc2 showed the process of fixing the display mechanism. TrueNAS 27’s choice of 6.18 LTS reflects a priority on stability.

In OpenZFS 2.4, optimization for AVX2 has advanced. AVX2 is an extension of parallel computation instructions. It is effective in processes such as checksums and compression. It is particularly significant for workloads involving repeated large-capacity reads and writes.

Background to the Introduction of TrueSearch

and WebShare

TrueNAS 27 adds TrueSearch. It is a mechanism that enhances server-side search functionality. In environments holding large volumes of data, search speed determines work efficiency. The key point is that users can search without retrieving everything to the client.

WebShare has also been newly added. It is a system set up for sharing. It is intended for external file exchange and internal publishing. Operation in combination with permission management is assumed.

Storage infrastructure is no longer just a repository. There is a trend toward integrating search and sharing as core functions. Users want to use data without being aware of its location. Administrators want to strictly control the scope of disclosure. Designs that satisfy both demands are required.

Operational Impact of Performance Improvements

The developers aim for significant performance improvements over the previous version. Kernel and OpenZFS updates contribute to this. AVX2 optimizations, improved hardware support, and detailed refinements add up. No specific figures have been published.

Performance is not just about speed. It also affects stability under concurrent connections and rebuild times. Faster recovery from failures means less impact on operations. Validation needs to cover both normal and abnormal conditions.

Fusion Pools 2.0 is also a point of interest. It is a mechanism that advances the combined use of fast storage devices and high-capacity devices. It enables operations that place frequently used data on the fast tier. It can be seen as a means to balance cost and speed.

Support for stateful SMB failover has also been added. It improves availability for Windows-based sharing protocols. It is designed to preserve connection state during failover. For business sharing infrastructure, avoiding downtime is the top priority.

Release Schedule and Challenges Toward the

December Final Release

This release is the first release candidate. Bug detection will proceed toward the final release. The release of TrueNAS 27.0 in December is set as the goal. It is a schedule to achieve stabilization in the remaining roughly two months.

TrueNAS Object Interface is provided as early access. It is a mechanism that allows direct use of ZFS datasets via S3 connections. S3 is the standard access protocol for object storage. It is seen as making integration with existing applications easier.

Prospective adopters are at the stage of urgently confirming behavior in test environments. They need to verify migration of existing share settings and user permissions. Configurations of fast and capacity tiers should also be considered in advance. It is important to have a system in place to track changes just before the final release.

Details are published on TrueNAS.com. Compatibility lists and known issues are updated as needed. In reporting by Michael Larabel of Phoronix, performance and hardware support improvements were highlighted as key points. Additional release candidates may appear before the final release.

Editorial Opinion

In the short term, validation work toward the December final release is expected to accelerate. Existing users will proceed with operational checks in test environments, entering a phase where bug reports concentrate. Resellers and integrators are expected to face pressure to update hardware compatibility lists.

In the long term, consolidation on a Linux foundation and standard S3 connectivity are assessed to change operational models. The boundary between file sharing and object storage may blur, with management on a single foundation likely to advance. Accumulated AVX2 optimizations are seen as increasing the capacity to handle larger volumes.

The remaining issue is how far the operational requirements for Fusion Pools 2.0 will be clarified. Verification is needed on whether stateful SMB failover remains stable in production environments. As usage patterns change, the question is what criteria operations teams will use to decide on migration.

References

• “TrueNAS 27 RC.1 Released: Linux 6.18 LTS + OpenZFS 2.4”, by Michael Larabel — Phoronix, 2026-10-06T00:25:45.000Z (ARR)
• Source URL: https://www.phoronix.com/news/TrueNAS-27-RC.1-Release