OpenZFS 2.3 is here, with RAID expansion and faster dedup
The latest version of OpenZFS offers RAID expansion, plus faster data deduplication donated by iXsystems. The code will be available very soon in the beta of TrueNAS SCALE 25.04.
OpenZFS release 2.3.0 is out, and will be in Linux distros that include ZFS, such as Ubuntu, Proxmox, NixOS and Void Linux – and eventually in FreeBSD, too. This release can be built for FreeBSD from 13.3 up to 14.2, and it is compatible with Linux kernel versions up to the latest LTS version 6.12.
The 2.3.0 version lets users expand an existing array by adding additional drives, and ZFS's built-in deduplication feature is now much faster. Advanced applications which do their own caching, such as some databases, can now bypass the ZFS Advanced Read Cache (ARC) with the new Direct IO support.
The RAID-expansion feature has taken a few years to arrive: we talked about it way back in February 2022. However, the OpenZFS team does have a good reason for moving slowly and cautiously: the last new-feature release of OpenZFS was version 2.2.0 in October 2023, which we looked at shortly beforehand. Unfortunately, that release was closely followed by the discovery of a data-corrupting bug. This had been lurking unseen for years, and was followed by fixed versions, both 2.2.2 and 2.1.14.
