Components required for Regional-DR

Regional disaster recovery (Regional-DR) relies on RHACM and Fusion Data Foundation components to support workloads and data mobility between clusters deployed across two IBM Fusion HCI sites.

Clusters

The Regional-DR brings the ability to failover applications and virtual machines (VMs) from one cluster to another cluster and then failback the same applications and VMs to the original primary cluster.

The following figure illustrates an example of the Regional-DR configuration for clusters deployed across two IBM Fusion HCI sites:
Figure 1. Illustration of a Regional-DR setup for base clusters
Illustration of a Regional-DR setup for base cluster
Figure 2. Illustration of a Regional-DR setup for HCP clusters
Illustration of a Regional-DR setup for HCP cluster
As shown in the figures Figure 1 and Figure 2, you can have the following clusters in the Regional-DR setup:
Table 1. List of clusters for Regional-DR setup
Cluster Description
Base cluster The cluster where the Fusion Data Foundation is installed in a provider mode and serves storage to different hosted control plane (HCP) clusters. Each IBM Fusion HCI site must have a minimum of one base cluster.
HCP cluster

The virtualized or bare metal hosted control plane (HCP) cluster where the Fusion Data Foundation client is installed. You can have multiple virtualized and bare metal HCP clusters in each site.

The version of the HCP clusters must be 4.18 or higher.
Hub cluster An external cluster where the RHACM operator is installed and created outside the IBM Fusion HCI sites. This hub cluster manages base clusters and hosted control plane (HCP) clusters of both IBM Fusion HCI sites.

Red Hat® Advanced Cluster Management for Kubernetes (RHACM) operator

The RHACM operator manages multiple clusters and application lifecycle. Hence, the RHACM hub cluster serves as a control plane in the Regional-DR setup.

RHACM operator is split into two parts:
  • RHACM hub: Run on the hub cluster or multicluster control plane.
  • Managed clusters: Imported base and HCP clusters to the hub cluster. The base or HCP cluster from the primary site is called a primary-managed cluster, while the one from the secondary site is called a secondary-managed cluster.

For more information about the RHACM, see Red Hat Advanced Cluster Management for Kubernetes documentation.

OpenShift Multicluster Orchestrator operator

The OpenShift® Multicluster Orchestrator operator orchestrates configuration and peering of the Fusion Data Foundation clusters for the Regional-DR configuration. It needs to be installed on the hub cluster.