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25.04 (Fangtooth) Development Notes

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Last Modified 2025-01-21 10:54 EST

25.04 Fangtooth

This page tracks the latest development roadmap and notes for the future TrueNAS major version 25.04 (Fangtooth).
See the stable 24.10 (Electric Eel) release notes for information relating to that version.

Features

25.04 (Fangtooth) will bring many new features and improvements to the TrueNAS experience:

RDMA over NFS support(Enterprise Feature) (NAS-129977)
iSCSI Fibre Channel support (Enterprise Feature)
Versioned TrueNAS API
User-linked API Keys (see Managing API Keys)
Improved UI Login Experience (NAS-130810).
Improved STIG Compliance and Security Focus (NAS-127235)
Enable support for ZFS Fast Deduplication (NAS-127088)

New and improved virtualization features.
Improvements to the TrueNAS apps service, including per-app selection of IP addresses (Electric Eel Apps and IP Addressing).

Obtaining a Release

Early releases of a major version are intended for testing and feedback purposes only. Do not use early release software for critical tasks.

For adventurous users that want to experiment with the latest feature development, 25.04 (Fangtooth) nightly images are available from the the TrueNAS downloads server.

More details are available from Software Releases.

Release Schedule

The release names and dates provided here are tentative and can change at any time.

TrueNAS^® | Enterprise™

Current

Software Lifecycle

TrueNAS Quality Lifecycle

TrueNAS releases follow a general adoption guideline for their lifetime. Starting with the NIGHTLY builds, each stage of a major release incorporates more testing cycles and bug fixes that represent a maturation of the release. With each version release stage, users are encouraged to install, upgrade, or otherwise begin using the major version, depending on the specific TrueNAS deployment and use case:

Release Stage	Completed QA Cycles	Typical Use	Description
NIGHTLY	0	Developers	Incomplete
ALPHA	1	Testers	Not much field testing
BETA	2	Enthusiasts	Major Feature Complete, but expect some bugs
RC	4	Home Users	Suitable for non-critical deployments
RELEASE	6	General Use	Suitable for less complex deployments
U1	7	Business Use	Suitable for more complex deployments
U2+	8	Larger Systems	Suitable for higher uptime deployments

The Software Status page shows the latest recommendations for using the various TrueNAS software releases.

Upgrade Notes

TrueNAS is an appliance built from specific Linux packages. Attempting to update TrueNAS with apt or methods other than the TrueNAS web interface can result in a nonfunctional system.
All auxiliary parameters can experience changes between TrueNAS major versions due to security and development changes. We recommend removing all auxiliary parameters from TrueNAS configurations before upgrading as these settings can result in SMB share failures after an upgrade.
After updating, clear the browser cache (CTRL+F5) before logging in to TrueNAS. This ensures stale data doesn’t interfere with loading the TrueNAS UI.
The TrueNAS REST API is deprecated in TrueNAS 25.04 and replaced by the TrueNAS websocket client. Full removal of the REST API is planned for a future release.
This new API Client is not the deprecated TrueNAS CLI (midcli). The API Client is integrated in TrueNAS 25.04 onwards. It provides the midclt command-line tool, and the means to easily communicate with middleware using Python to make calls through the websocket API.
This API client allows for better integration of TrueNAS into third-party solutions. Use this as a reference for projects that require direct TrueNAS integration.
TrueNAS API documentation remains available in the UI and through the TrueNAS Documentation Hub.
The default libvirt account UID and GID is changed to to avoid possible clashes with user created Active Directory (AD) users. TrueNAS automatically updates libvirt UID and GIDs when upgraded to 25.04. Users attempting revert to 24.10 or an earlier release must manually review and update libvirt-qemu user and group IDs back to the values that were default in that version (64055:64055 for 24.10).

Migrating Virtual Machines

TrueNAS 25.04 changes the virtualization hypervisor backend from the previous KVM implementation (TrueNAS 24.10 and earlier) to Incus for virtual machine (VM) deployment and adds support for linux system containers (LXC), with lightweight isolation functionality similar to jails in TrueNAS CORE. This is an experimental community feature, with full Enterprise support planned for a future TrueNAS release version.

Manual Migration Required
Due to configuration incompatibilities between the previous KVM hypervisor implementation (TrueNAS 24.10 and earlier) and Incus in TrueNAS 25.04 (and later), existing VMs do not automatically migrate on upgrade from 24.10.X to 25.04. However, storage zvols are retained, allowing users to easily recreate previously configured VMs.

Manual Migration Instructions

To manually migrate VMs from 24.10 (latest) to 25.04, users should first prepare to migrate by gathering image files and recording existing configuration settings. After updating to 25.04, use the configuration details gathered above to recreate VMs with the same resource allocations and mount existing storage zvols.

Preparing to Migrate VMs from 24.10

Screenshot or record existing VM configuration(s).
Go to Virtualization and click on a VM to expand that row. Click Edit to open the Edit VM screen and note the existing configuration. Save your configuration settings in an external location to reference later. These settings do not migrate and must be recreated after upgrading to 25.04.
Record the existing zvol storage location and virtual device configuration.
Go to Virtualization and click on a VM to expand that row. Click Devices. Click in the Disk row and select Edit. Note the configured path in Zvol as well as the storage Mode and the Disk Sector Size. Continue to note all other VM devices and associated configuration settings. Record this information in an external location along with the configuration settings gathered above.
Locate or download the required iso image files.
Access the VM via Display or Serial Shell and confirm the installed OS and version. Refer to documentation for the installed OS if needed to locate the installed version.
If the installed image (iso) file is stored on the TrueNAS system or in an external location, note this path and record it along with the other configuration settings. If needed, download a fresh image file matching the installed OS and Version

Recreating VMs in 25.04

After upgrading to 25.04, go to Virtualization and click Select Pool to open the virtualization Global Settings screen. Use the Pool dropdown to select a pool for virtualization service storage. Accept default networking settings or modify as needed, then click Save.
Click Create New Instance and recreate previous VM configuration(s).
Select VM for Virtualization Method and select or upload the iso file in Image. Using the configuration settings you recorded before updating, replicate the previous VM configuration.
Select the existing zvol for the VM as the storage source in Disks. Click Create.

Upgrade Paths (Anticipated)

The chart below shows recommended paths for upgrading from earlier TrueNAS versions.

Update the system to the latest maintenance release of the installed major version before attempting to upgrade to a new major version.

Permitted upgrade methods are:

update: apply an automatic update using the Update screen in the TrueNAS UI or install a manual update file. Some upgrade paths do not support these options (see chart).
ISO install: save a current TrueNAS configuration file, perform a fresh install using an .iso file for the target version, and then upload the previously saved configuration.

Users can skip major versions with a fresh ISO install followed by a configuration file upload. Carefully review release notes for each skipped major version before upgrading, noting any service deprecations or significant changes that impact the previous configuration. Consider stopping at major versions with significant impacts to address changes before continuing the upgrade path or be prepared to manually reconfigure incompatibilities on the latest target version.

          flowchart LR
            A["11.3-U5"] -->|update| B["12.0-U8.1"]
            B -->|"update

ISO install"| C["13.0-U6.4

13.3-U1"]
            C -->|ISO install| H
            C -->|"(anticipated)"| I
            D["22.02.4 (Angelfish)"] -->|update| E
            E["22.12.4.2 (Bluefin)"] -->|update| F
            F["23.10.2 (Cobia)"] -->|update| G
            G["24.04.2.5 (Dragonfish)"] -->|update| H
            H["24.10.1 (Electric Eel)"] -->|"(anticipated)"| I
            I["25.04.0 (Fangtooth)"]

          flowchart LR
            A["11.3-U5"] -->|update| B
            B["12.0-U8.1"] -->|update| C
            C["13.0-U6.4"] -->|"(anticipated)"| F
            C["13.0-U6.4"] -->|"(anticipated)"| G
            D["23.10.2 (Cobia)"] -->|update| E
            E["24.04.2.5 (Dragonfish)"]  -->|"(anticipated)"| F
            F["24.10.1 (Electric Eel)"] -->|"(anticipated)"| G
            G["25.04.0 (Fangtooth)"]

Component Versions

Click the component version number to see the latest release notes for that component.

Component	Version
Linux Kernel	6.12
OpenZFS	2.3.0-2
Docker Engine	27.3.1

OpenZFS Feature Flags

TrueNAS integrates many features provided by the upstream OpenZFS project. Any new feature flags introduced since the previous OpenZFS version that was integrated into TrueNAS (OpenZFS 2.2.99) are listed below:

Feature Flag	GUID	Notes
fast deduplication	com.klarasystems:fast_dedup	This flag is present in 24.10, but is now generally available through the TrueNAS UI.

For more details on feature flags, see OpenZFS Feature Flags and OpenZFS zpool-feature.7.

25.04 Nightly Development Changelog

The TrueNAS REST API is deprecated in TrueNAS 25.04 and replaced by the TrueNAS websocket client. Full removal of the REST API is planned for a future release.
The default libvirt account UID & GID is changed to a less common value to avoid clashing with user created UID/GIDs. See Upgrade Notes above for more information (NAS-131695).
Improved API key mechanism with support for user-linked API keys (NAS-131396). Existing API keys created via the TrueNAS API (not UI or TrueCommand) that specify an allow list with white-listed API methods are revoked upon upgrade because there is no clean way to migrate to the new system. Legacy API keys from TrueNAS 24.10 or earlier migrate to the root, admin, or truenas_admin account, depending on server configuration

Use Cases

Industry

Support

Resources

25.04 (Fangtooth) Development Notes

Features

Obtaining a Release

Release Schedule

TrueNAS Quality Lifecycle

Upgrade Notes

Migrating Virtual Machines

Preparing to Migrate VMs from 24.10

Recreating VMs in 25.04

Upgrade Paths (Anticipated)

Component Versions

OpenZFS Feature Flags

25.04 Nightly Development Changelog