TrueNAS 25.10 with NVMe-oF Support, Faster API, and New OpenZFS

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Storage provider iX Systems Inc. has released TrueNAS 25.10, the second pure GNU/Linux-based version of its NAS operating system. The standout new feature of the new version is NVMe-oF (NVMe over Fabrics), a protocol standard that extends the high-performance and low latency of NVMe SSDs to network-distributed storage architectures.

High-speed storage beyond the local PCIe bus

While classic NVMe (Non-Volatile Memory Express) was originally developed for direct access to flash storage via the PCIe bus within a server, NVMe-oF allows the same command set to be used over the network, or “fabric.” For years, NVMe has been replacing the aging AHCI protocol and utilizes PCIe lanes more efficiently.

However, classic NVMe drives are tied to their respective hosts. In modern data centers with AI, virtualization, containerization, or scalable storage clusters, this is a bit inflexible. NVMe-oF solves this problem by transporting the NVMe stack over a network—in principle comparable to iSCSI or Fibre Channel. This should make it possible to access very large NVMe arrays directly from TrueNAS 25.10.

RDMA: Community Edition without “Turbo Mode”

Paying enterprise customers can leverage the full potential of NVMe-oF. RDMA-capable network cards (Remote Direct Memory Access) then allow direct memory access via NVMe/RDMA, NVMe/RoCE, or NVMe/InfiniBand. Simply put, with RDMA, a network card can exchange data directly between two systems without the host's CPU or operating system having to copy or route the data through the kernel. This results in extremely low latency, hardly any CPU load, and thus high data throughput.

The Community Edition of TrueNAS 25.10 can only connect NVMe arrays via TCP/IP (NVMe-oF/TCP). The significantly higher latencies and higher CPU load are offset by a cost advantage, as all standard network cards (without RDMA) can be used in this case. RDMA-capable network cards, with different RDMA types each, are available from Intel, Mellanox/NVIDIA, Broadcom, and Marvell/Cavium, for example. For enterprise customers, both variants even support 400GbE networks, according to iXsystems.

Brand new OpenZFS and a faster API

TrueNAS 25.10 ships with the current OpenZFS 2.3.4. In addition to the usual bug fixes, OpenZFS 2.3.4 has revised algorithms for storage pool allocation, which distribute data better across individual drives. This leads to faster write operations, more consistent performance, and lower latency, especially under heavy load.

New in TrueNAS 25.10 is the versioned TrueNAS API, based on JSON-RPC 2.0 over WebSocket. It replaces the previous REST API and enables significantly faster and more responsive communication, benefiting both the web interface and future third-party plug-ins (the TrueNAS blog mentions Kubernetes, VMware vSphere, and Proxmox VE). The API documentation can be found at api.truenas.com.

There are also improvements for virtual machines: Secure Boot is supported, and it is possible to import and export disk images in common formats such as QCOW2, RAW, VDI, VHDX, and VMDK. Enterprise customers finally get HA failover for KVM-based VMs with “TrueNAS high-availability appliances”.

TrueNAS updates now with different risk levels

After iXsystems von its FreeBSD roots and around half of its loyal customer base, it seems that the FreeBSD principle of slow but 100 percent stable updates has also been abandoned. Development based on GNU/Linux is progressing faster and perhaps offers such interesting features as an update system with different risk profiles for this reason. The willingness to take risks cannot be adjusted via a percentage slider but via profiles: Early Adopter, Developer, General, and Mission Critical.

The web interface has received several improvements, including an enhanced Apps YAML editor with syntax highlighting and validation, a more intuitive iSCSI wizard, and a simplified page for creating new users. System statistics and monitoring dashboards are said to respond significantly faster.

All changes in TrueNAS 25.10 “Goldeye” are explained in detail in the iXsystems blog. The free Community Edition can be downloaded after registration; enterprise customers need to contact sales.

(mki)