ACM hub disaster recovery: passive copy or active move to a new hub

mika published on 2026-10-15 included in Openshift

High-level walkthrough of a guided lab that backs up a running Red Hat Advanced Cluster Management (ACM) 2.17 hub and restores it onto a brand-new Single Node OpenShift (SNO) hub while the primary stays up, in two scenarios: passive (copy the hub, the managed clusters stay where they are) and active (the managed clusters move to the new hub). The full lab (modules, manifests, scripts and an animated flow diagram) lives in the acm-dr repository.

Disconnected OSUS on OpenShift

mika published on 2026-09-15 included in Openshift

Manifests to reproduce this lab: osus-lab.

Configuring the OpenShift Update Service (OSUS) for a cluster that pulls images through an Artifactory mirror, with the OSUS graph scrape served from a small dedicated repo. Built and validated on a Single-Node OpenShift (SNO) lab.

Core of this is OSUS + manifest-only mirroring (§0, §2-§10). §1 (DNS) is only needed if Artifactory doesn’t already resolve in your environment — skip it if yours does.

Reset the OpenShift kubeadmin password

mika published on 2026-06-12 included in Openshift

Reset the kubeadmin bootstrap password when the original credential is lost and no other cluster-admin identity provider is available.

Prerequisites

SSH access to a control plane node (as core, with sudo if required).
oc available on the node or copied in with the recovery kubeconfig.
htpasswd available to generate the bcrypt hash (install httpd-tools on RHEL, or run from a toolbox/UBI container).
A new password of at least 23 characters (required by the bootstrap authenticator).

Warning

This procedure patches the kubeadmin secret in kube-system. Use only for cluster recovery. After restoring access, define an identity provider and create a dedicated cluster-admin user, then remove kubeadmin per Red Hat documentation.

1. SSH to a control plane node

Connect to any healthy control plane node in the cluster.

Monitor RHOAI usage with Cluster Observability Operator and Perses

mika published on 2026-04-21 included in Openshift

Deploy the Cluster Observability Operator with its Perses UI plugin, then apply a PersesDashboard that surfaces Red Hat OpenShift AI workbench, pipeline server, and model-serving metrics directly in the OpenShift web console.

Build a RHEL Image Mode ISO with bootc-image-builder

mika published on 2026-04-14 included in Linux

Build an installable ISO from a RHEL bootc container image using bootc-image-builder

Enable LLDP on OpenShift nodes using nmstate

mika published on 2026-02-18 included in Openshift

This article describes how to enable LLDP (Link Layer Discovery Protocol) on all Ethernet interfaces that are up, using the nmstate operator and a NodeNetworkConfigurationPolicy (NNCP).

Prerequisites: the Kubernetes NMState operator is installed and a NMState instance exists (see Configure OCP network using nmstate operator).

1. Apply the NodeNetworkConfigurationPolicy

The policy below uses nmstate capture to select only Ethernet interfaces that are in state up, then sets lldp.enabled: true on those interfaces. This avoids touching other interface types or down interfaces.