Is it supported to modify the control plane node size in a running OpenShift Container Platform 4.x cluster?

Solution Verified - Updated -

Environment

  • Red Hat OpenShift Container Platform 4.6.

Issue

  • Resizing of a control plane node is not supported as stated in Red Hat official documentation.
  • How more resources can be added to the master nodes without reinstalling the cluster ?

Resolution

  • At the time when this article is being written (current major latest version: 4.6), resizing (shut down the master node, modify its memory and/or CPU and start up again) is only supported for clusters installed following Bare Metal User Provisioned Infrastructure
  • For clusters with any cloud provider integration configured, the only method currently supported is to remove and re-provision the master nodes one by one as explained on our official documentation.
  • Cautions:
    • Make sure that the rest of the masters are completely healthy before removing or shutting down one of them.
    • Removing or shutting down a master may be a risky operation in an overloaded or unhealthy cluster. You can open a support case if your cluster is in this situation, you have to increase the hardware of your master nodes and you need some guidance.
  • There is an RFE requesting for master resizing (as explained on the first point) supportability on any cluster.
  • There is a documentation bug (BZ1842424) reporting the incompleteness of the sentence written here in this regard.

This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.