On January 11, 2026, at 2:48 PST, an emergency support request was opened for OSD crashes in v20.2.0 that rendered CephFS inaccessible.

The incident was resolved, restoring cluster availability.

A secondary post-recovery issue related to scrubbing errors was subsequently identified and fixed.

The fix involved deploying a new build of Ceph that contained the patches for the bugs. The engineering team made use of Clyso's new build system, delivering the fix to the client as fast as possible.

Below are a list of known bugs in ceph versions that we want to highlight. As of time of writing this, the latest versions for each release are the following:

• reef: 18.2.7
• squid: 19.2.3

There are more bugs in Ceph that were not included here, we've highlighted a few that we wanted to share.

Cross-version Issues​

These critical bugs affect multiple major versions of Ceph.

RadosGW --bypass-gc Data Loss Bug​

Severity: Critical
Affected Versions: Quincy (17.2.x), Reef (18.2.x), Squid (19.2.x) Bug Tracker: https://tracker.ceph.com/issues/73348

An S3 system holds data—call it source. It keeps applications running, but migration is needed, maybe due to scale limits or costs creeping up. A new S3 setup, target, is set to replace it. The challenge is to move all data from source to target with no downtime, no data lost, and no breaks for the apps using source. What can get this done?

We see on some Kubernetes cluster upgrading from 1.30 -> 1.31 following errors on cilium, coredns, kube-proxy, ... pods on Control Planes:

In 2023, Clyso released the Ceph Analyzer, giving your operations teams a great tool for inspecting the health of your Ceph clusters, offering in-depth reporting and recommendations to fix many non-trivial issues. Two years later, we are pleased to announce the release of Clyso Kubernetes Analyzer!

One of my favourite things to assist users with is simplifying their workflows for making major changes to their Ceph clusters, such as adding or removing multiple hosts at once. Ceph is inherently excellent at handling these tasks – one of its greatest strengths is the ability to transparently add or remove capacity, replace servers, and perform maintenance, all without downtime.

Managing cloud resources can be complex, especially when you work across multiple cloud providers. That’s where MCB (Multi-Cloud Broker) comes in—a powerful platform designed to simplify and unify cloud management, enabling users to interact with various cloud services through a single interface.