Fedora CoreOS 45 Test Week kicks off Next Week September 21
Community testers are being called in to vet Fedora's container-optimized OS ahead of the Fedora 45 final release.
The Fedora CoreOS and QA teams are running a Fedora CoreOS Test Week starting Monday, September 21, 2026. The idea is to hand the community container-optimized images built from Fedora 45 content and get them to run before those images reach the public testing and stable streams.
Lukáš Růžička, a Fedora QA member, posted the call on Fedora Magazine on September 16, a day after Fedora 45 Beta shipped. "By participating, you help us ensure a smooth and reliable experience for all users," he wrote. "Your contribution, big or small, makes a huge difference."
Why this matters
The timing isn't arbitrary. Fedora runs on a roughly six-month cadence. Fedora 44 landed April 28, 2026, the 45 Beta dropped September 15, and the final 45 is expected November 19, following the usual third-Thursday-of-November pattern. FCOS is one of the project's five first-class editions, so its Test Week doubles as a quality gate for production-grade cloud and bare-metal deployments.
That last point is worth dwelling on. A Test Day like this is really just community members hammering on pre-release software so the actual teams don't have to do it blind. Low risk for testers, high value for everyone who eventually deploys.
What Fedora CoreOS actually is
Fedora CoreOS is the spiritual successor to Container Linux, the container-optimized system Red Hat acquired back in 2018. If you used that years ago, FCOS is what grew out of it. It's now a full edition alongside Workstation, KDE Plasma Desktop, Server, and IoT.
At its core, FCOS is an immutable, image-based OS. The base ships as an OSTree commit rather than getting patched in place the way a traditional distro does. You manage packages through rpm-ostree for atomic, rollback-able updates and run apps in containers via Flatpaks and Podman. Updates stage in the background and apply on reboot. It's also hardened out of the box: SELinux, firewalld, TPM 2.0, LUKS disk encryption, and signature verification on every commit.
Two FCOS-specific changes from the F45 Beta are what this Test Week will try to break. First, systemd-oomd and zram swap support are now in place, bringing FCOS in line with other Fedora variants on memory-pressure handling and RAM-based swap. Second, Ignition now accepts Butane YAML configs natively alongside its traditional JSON, which should make machine configuration a bit less awkward for people who prefer YAML.
How to get involved
Participation follows the standard Fedora Test Day workflow, and the design deliberately keeps the barrier low. Download the test images from the wiki page, work through the step-by-step test cases, run them on your own hardware or a virtual machine, then log each pass or fail back on the wiki. Bugs get funneled through the Fedora CoreOS issue-tracking workflow.
Here's a bit of context that helps explain the rhythm. Fedora CoreOS 43 ran September 22-26, 2025 under Yasmin Valim de Souza, and Fedora CoreOS 44 had a Test Day March 23-27, 2026 organized by Kamil Páral and Yasmin Valim de Souza. This autumn event targets the "X+2" release and complements a spring CoreOS-focused session.
The FCOS 45 images themselves pull from the same Fedora 45 content that Aoife Moloney, Fedora Operations Architect, announced with the Beta. Broader F45 changes that touch infrastructure FCOS leans on include kmscon replacing the legacy in-kernel fbcon console, enforced package-signature checking by default, and major version bumps like Podman 6 and GCC 16.2.
If you want to dig in, start at the wiki Test Day page, which holds the authoritative test-case list and the download links. The discussion forum thread and the Fedora CoreOS tracker on GitHub are good spots for questions and logging results, and you can also find the team in the #coreos and #qa Matrix rooms or on the test mailing list.
Head here to the Fedora CoreOS 45 Test Day wiki page for the case list.
