FreeBSD 15.1 Beta 2 Released with Zstd 1.5.7 and Kernel Bug Fixes

FreeBSD 15.1 Beta 2 Released with Zstd 1.5.7 and Kernel Bug Fixes

The second beta of FreeBSD 15.1 arrived on May 8, bringing compression library updates, bsdinstall improvements, and a raft of userland and kernel fixes — keeping the project on track for a June 2 stable release.

The FreeBSD Release Engineering team announced the availability of FreeBSD 15.1-BETA2 on May 8, 2026 — one week after Beta 1 dropped on May 2. The release continues the project’s steady march toward the next minor version update in the FreeBSD 15 series, with a stable release currently targeted for June 2, 2026.

Zstd Updated to 1.5.7

The most visible improvement in Beta 2 is the update of the bundled Zstd compression library to version 1.5.7, bringing FreeBSD in line with the latest upstream release of the widely-used compression standard. Zstd is used pervasively throughout the system, from kernel module compression to package management, making this an important baseline update.

bsdinstall Package Bootstrap Fix

A notable installer improvement lands in this beta: bsdinstall now consistently uses pkg.freebsd.org as the package repository when performing bootstrap operations. Previously, inconsistent repository selection during installs could cause unexpected behavior; this fix ensures the official FreeBSD package repository is always the target during initial system setup.

Userland Utility Bug Fixes

Several userland tools received bug fixes in this cycle. The affected utilities include ifconfig, lockf, stat, tail, and certctl. Additionally, manual page updates were included across the tree.

Kernel: nullfs, so_splice, and VT Fixes

In kernel space, bugs were addressed in three areas: the nullfs filesystem layer, the so_splice socket interface, and the VT (vt(4)) console subsystem. These are stability-focused fixes consistent with the beta phase’s goal of hardening the system before release.

Scheduler Selection Framework

A notable architectural addition for the 15.1 release cycle — introduced prior to Beta 2 — is the scheduler selection framework. This allows users to choose between different CPU schedulers (such as SCHED_ULE and SCHED_4BSD) at boot time by adjusting a kernel tunable (kern.sched). The GENERIC kernel configuration for amd64 now includes both schedulers. This is the first time FreeBSD has offered this level of scheduling flexibility out of the box.

Beta 3, RC, and the Road to June 2

Following Beta 2, the project expects to publish Beta 3 around May 15, followed by the first Release Candidate approximately a week later. If the RC phase proceeds without major issues, FreeBSD 15.1-RELEASE is scheduled to ship on June 2, 2026.

One anticipated feature that will not be part of the 15.1 release is the KDE Plasma desktop installer option via bsdinstall. Work on that feature has been deferred and is now targeted for FreeBSD 15.2.

Beta builds are available for download from the FreeBSD mirrors and are suitable for testing on non-production systems. The FreeBSD project encourages developers and early adopters to test their workloads against Beta 2 and report any issues via the official bug tracker at bugs.freebsd.org.