Planning a bare metal cluster for OKD Virtualization

If you will use OKD Virtualization, it is important to be aware of several requirements before you install your bare metal cluster.

  • If you want to use live migration features, you must have multiple worker nodes at the time of cluster installation. This is because live migration requires the cluster-level high availability (HA) flag to be set to true. The HA flag is set when a cluster is installed and cannot be changed afterwards. If there are fewer than two worker nodes defined when you install your cluster, the HA flag is set to false for the life of the cluster.

    You can install OKD Virtualization on a single-node cluster, but single-node OpenShift does not support high availability.

  • Live migration requires shared storage. Storage for OKD Virtualization must support and use the ReadWriteMany (RWX) access mode.

  • If you plan to use Single Root I/O Virtualization (SR-IOV), ensure that your network interface controllers (NICs) are supported by OKD.

Choosing a method to install OKD on bare metal

You can install OKD on installer-provisioned or user-provisioned infrastructure. The default installation type uses installer-provisioned infrastructure, where the installation program provisions the underlying infrastructure for the cluster. You can also install OKD on infrastructure that you provision. If you do not use infrastructure that the installation program provisions, you must manage and maintain the cluster resources yourself.

See Installation process for more information about installer-provisioned and user-provisioned installation processes.

Installing a cluster on installer-provisioned infrastructure

You can install a cluster on bare metal infrastructure that is provisioned by the OKD installation program, by using the following method:

Installing a cluster on user-provisioned infrastructure

You can install a cluster on bare metal infrastructure that you provision, by using one of the following methods:

  • Installing a user-provisioned cluster on bare metal: You can install OKD on bare metal infrastructure that you provision. For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

  • Installing a user-provisioned bare metal cluster with network customizations: You can install a bare metal cluster on user-provisioned infrastructure with network-customizations. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations. Most of the network customizations must be applied at the installation stage.

  • Installing a user-provisioned bare metal cluster on a restricted network: You can install a user-provisioned bare metal cluster on a restricted or disconnected network by using a mirror registry. You can also use this installation method to ensure that your clusters only use container images that satisfy your organizational controls on external content.