TrueNAS 12.0-U3 was released yesterday and marks an important milestone in the transition from FreeNAS to TrueNAS. TrueNAS 12.0 is now considered by iXsystems to be a higher quality release than FreeNAS 11.3-U5, our previous benchmark, and is now ready for mission-critical enterprise deployments. The new TrueNAS documentation site has also reached a point where it has more content and capabilities than FreeNAS.
TrueNAS 12.0 is the official merger of FreeNAS and TrueNAS into a unified software image accompanied by a long list of features and performance improvements. Nearly all of the significant bugs were resolved in TrueNAS 12.0-U2.
With new features, improved performance, and higher quality, TrueNAS 12.0-U3 becomes the default release for new systems. Any new bugs or security vulnerabilities found in FreeNAS 11.3 will be resolved through updates in TrueNAS 12.0. Therefore, FreeNAS 11.3-U5 will be the last FreeNAS release.
How did we make that assessment? Over 50% of FreeNAS 11.3 systems and 20% of TrueNAS Enterprise systems have upgraded to TrueNAS 12.0. These transitions since 12.0-U2 have been very smooth. With TrueNAS 12.0, OpenZFS 2.0 has outperformed the previous versions of ZFS both in our lab and user environments and has proven to be even more robust in large scale deployments.
TrueNAS 12.0-U3 resolves some minor bugs and is an easy web update. However, we do recommend waiting to update your systems zpool feature flags until you are finished validating your performance and functionality.
The history of TrueNAS 12.0 releases has been:

• TrueNAS 12.0 RELEASE was made available October 20, 2020, and included many new features along with OpenZFS 2.0 support.
• TrueNAS 12.0-U1 was released in December, resolved the most significant bugs, and enabled a few new features like Fusion pools and more efficient scrubbing and resilvering.
• TrueNAS 12.0-U2 was released in February, and included many bug fixes and some minor features. A minor update to 12.0-U2.1 was provided to reduce some alerts seen by users.
• TrueNAS 12.0-U3 was officially released April 13, 2021, and includes many bug fixes and some minor features. A full list of changes and bugs is available for those with an account on the TrueNAS Jira bug tracker.

Issues resolved in TrueNAS 12.0-U3:
Four new features, seven improvements, and about 140 bug fixes are included. Many of these are minor reporting or web UI issues. For the M-Series, we’ve added the ability to remotely upgrade and downgrade NVDIMM firmware. For all platforms, there are improvements to ZFS ARC and network interface statistics.
TrueNAS 12.0 Documentation is Now More Extensive Than 11.3
TrueNAS 12.0 has moved to a more modern documentation style that encourages and simplifies user and community contribution. The new modular TrueNAS documentation is now more comprehensive than FreeNAS was. We’ve completed an initiative to simplify navigation and improve usability. Please check out the new TrueNAS documentation even if you don’t upgrade today. We’re extremely grateful for all the contributions received thus far and encourage more user suggestions going forward. See below for an example of the new docs site and menu system.

TrueNAS Quality Lifecycle
While releasing TrueNAS 12.0, we created a new lifecycle model for TrueNAS CORE and Enterprise releases. The table below summarizes our current process and the dates for TrueNAS 12.0. We always recommend that mission critical use cases should also wait for a version to be widely deployed before deploying it themselves. TrueNAS 12.0-U2.1 was very good and with 12.0-U3, we expect to meet our quality goals.

FreeNAS to TrueNAS 12.0 Upgrades are Easy
TrueNAS 12.0-U3 is compatible with all of the iXsystems platforms from the FreeNAS/TrueNAS Minis, to the power-efficient X-Series, all the way up to the flagship High Availability (HA) M-Series. There is also a new R-Series product line that can run CORE, Enterprise, and SCALE editions of TrueNAS. All of these can be updated via the web UI.
For those with FreeNAS installed on your system, we recommend upgrading to FreeNAS 11.3-U5 first and then upgrading to TrueNAS 12.0-U2 with a single click to retain roll-back options. Otherwise, download TrueNAS 12.0-U3 to get started.
For those with TrueNAS HA systems and support contracts, we recommend contacting iXsystems support to schedule an upgrade. We will verify your systems’ health, configuration, and support the upgrade process as part of the “white glove” service that comes with any support contract.
TrueCommand 2.0 is coming
TrueNAS 12.0 also includes support for TrueCommand and TrueCommand Cloud, a SaaS version that includes a VPN capability for managing across private networks. TrueCommand Cloud is generally available and is based on TrueCommand 1.3.2. 
TrueCommand 2.0 will add new functionality to TrueNAS 12.0 deployments. More information will be available later this month. TrueCommand 2.0 trials have been going well and include a storage navigator for browsing and snapshotting files, directories, and datasets. Please contact iXsystems if you are a TrueCommand user and interested in early access to TrueCommand 2.0.

TrueNAS CORE: Still the best Free NAS
TrueNAS 12.0-U3 improvements continue to make it the best free NAS system available. If you have any questions or comments, we’d love to hear them on the community forums, on the TrueNAS subreddit, or in response to this blog. If you need additional information on how TrueNAS can streamline, accelerate, and unify data management for your business, please contact us.