Chapter 2. Requirements for enabling Regional-DR

Disaster Recovery features supported by Red Hat OpenShift Data Foundation require all of the following prerequisites in order to successfully implement a Disaster Recovery solution:

  • Subscription requirements

    • A valid Red Hat OpenShift Data Foundation Advanced entitlement
    • A valid Red Hat Advanced Cluster Management for Kubernetes subscription

    To know how subscriptions for OpenShift Data Foundation work, see knowledgebase article on OpenShift Data Foundation subscriptions.

  • You must have three OpenShift clusters that have network reachability between them:

    • Hub cluster where Advanced Cluster Management for Kubernetes (RHACM operator), ODF Multicluster Orchestrator and OpenShift DR Hub controllers are installed.
    • Primary managed cluster where OpenShift Data Foundation, OpenShift DR Cluster controller, and applications are installed.
    • Secondary managed cluster where OpenShift Data Foundation, OpenShift DR Cluster controller, and applications are installed.
  • Ensure that RHACM operator and MultiClusterHub is installed on the Hub cluster. See RHACM installation guide for instructions.

    • Login to the RHACM console using your OpenShift credentials.
    • Find the Route that has been created for the Advanced Cluster Manager console:

      $ oc get route multicloud-console -n open-cluster-management -o jsonpath --template="https://{.spec.host}/multicloud/clusters{'\n'}"

      Example Output:

      https://multicloud-console.apps.perf3.example.com/multicloud/clusters

      After logging in using your OpenShift credentials, you should see your local cluster imported.

  • Ensure that you have either imported or created the Primary managed cluster and the Secondary managed clusters using the RHACM console.
  • The managed clusters must have non-overlapping networks.

    To connect the managed OpenShift cluster and service networks using the Submariner add-ons, you need to validate that the two clusters have non-overlapping networks by running the following commands for each of the managed clusters.

    $ oc get networks.config.openshift.io cluster -o json | jq .spec

    Example output for cluster1 (for example, ocp4perf1):

    {
      "clusterNetwork": [
        {
          "cidr": "10.5.0.0/16",
          "hostPrefix": 23
        }
      ],
      "externalIP": {
        "policy": {}
      },
      "networkType": "OpenShiftSDN",
      "serviceNetwork": [
        "10.15.0.0/16"
      ]
    }

    Example output for cluster2 (for example, ocp4perf2):

    {
      "clusterNetwork": [
        {
          "cidr": "10.6.0.0/16",
          "hostPrefix": 23
        }
      ],
      "externalIP": {
        "policy": {}
      },
      "networkType": "OpenShiftSDN",
      "serviceNetwork": [
        "10.16.0.0/16"
      ]
    }

    For more information, see Submariner add-ons documentation.

  • Ensure that the Managed clusters can connect using Submariner add-ons. After identifying and ensuring that the cluster and service networks have non-overlapping ranges, install the Submariner add-ons for each managed cluster using the RHACM console and Cluster sets. For instructions, see Submariner documentation.