OpenShift 4.18.54 can override a cgroups v1 setting during upgrade

Red Hat has documented a verified OpenShift Container Platform issue in which an upgrade from 4.18.46 to 4.18.54 moved cluster nodes from cgroups v1 to cgroups v2 despite an explicit v1 configuration. The company says applications that depend on cgroups v1 failed after the change. The support article was updated on September 13.

What Red Hat describes

The affected cluster had cgroupMode: v1 set in the nodes.config.openshift.io/cluster resource, according to Red Hat. Nevertheless, the nodes migrated to cgroups v2 during the 4.18 update. The public portion of the verified solution lists OpenShift versions 4.13 through 4.18 in its environment section, although the specific upgrade path described is 4.18.46 to 4.18.54.

Red Hat keeps the diagnosis and remediation behind its subscriber login. The public page therefore establishes the observed behavior and impact but does not expose the corrective procedure.

Why platform teams should check before upgrading

This is not a cosmetic configuration mismatch. Red Hat explicitly ties the unexpected migration to failures in applications that rely on cgroups v1. Teams preparing the same OpenShift 4.18 update should identify workloads with a hard dependency on cgroups v1 before proceeding rather than assuming the configured mode will remain unchanged.

A cautious upgrade plan should include checking the cluster’s configured cgroup mode before maintenance, confirming the effective mode on nodes after the update, and exercising legacy workloads in a representative environment. Customers on the affected path should consult the full Red Hat solution or open a support case for the vendor’s remediation guidance.

The scope language deserves care: Red Hat lists several OpenShift release families as the environment, but its published issue statement names one concrete transition, from 4.18.46 to 4.18.54. Until Red Hat publishes broader reproduction details, operators should not infer that every listed version or upgrade path behaves identically.