Offshoots of cancelled TrueNAS Core upgrade to FreeBSD 15

Good news if you want to keep your NAS boxes on FreeBSD – two new contenders just stepped up, with updated forks of the cancelled TrueNAS Core.

FreeBSD has a strong reputation as a stable server OS, and integrates highly reliable ZFS filesystem right into its kernel.

The snag is that Linux is rather more widespread, meaning more people know their way around a Linux box – but Linux knowledge doesn’t transfer well over to FreeBSD.

The Reg FOSS desk just found out about two different new dedicated NAS OS based on FreeBSD – and saliently, based on the current FreeBSD 15 codebase, which was released in December 2025, with version 15.1 arriving in June.

FreeCORE-15.0-U1 appeared on August 27th.

It’s the first update for FreeCore 15.0, which appeared just a week earlier.

The FreeCORE project website describes it as “TrueNAS® CORE — continued”, and says: “FreeCORE carries the TrueNAS CORE 13.3 system forward as an independently maintained operating system on FreeBSD.

“15.0-U1 is stable.

TrueNAS CORE 13.3 systems upgrade straight to 15.0 in place, then continue on the project’s update train.” The reason that anyone needed to come along and carry the TrueNAS Core system forward is that developer and vendor iXsystems cancelled its FreeBSD-based NAS OS in 2024.

This followed two years after it introduced its new TrueNAS SCALE NAS OS, which is based on Debian Linux.

To Register sister site Blocks&Files, the company explained no one was being marooned by the change.

Some TrueNAS Core users – and this vulture is one of them – were less than delighted by the change.

OpenZFS works fine on Linux, and it’s regularly updated, but it must be loaded as a module: license restrictions mean it cannot be built into the Linux kernel.

Significantly, this means that the ZFS Adaptive Replacement Cache must remain separate from Linux’s Page Cache.