Chapter 4. Supported configurations

Red Hat OpenShift Container Storage 4.2 is deployed as a minimal cluster of 3 worker nodes. Spread the nodes across three different availability zones to ensure availability.

Each node in this initial cluster runs one 2 TiB disk, which replicate their contents to each other, providing a usable starting capacity of 2 TiB. The initial cluster will consist of 3 nodes, regardless of the number of nodes selected for storage nodes.

The initial cluster can later be expanded to a maximum of 9 nodes that support up to 9 disks for a 3 node cluster.

The following table shows the supported configurations for OpenShift Container Storage.

Table 4.1. Supported configuration across 3 nodes

 Number of nodesDisksTotal capacityUsable storage capacity

Initial configuration

3 Nodes

1 disk of 2 TiB on each node

6 TiB

2 TiB

Possible expansion

Maximum of up to 9 nodes

3 disks of 2TiB on each node, which is a maximum of 27 disks of 2 TiB each

Maximum of 54 TiB

Maximum of 18 TiB

Note

The distribution of the disks depends on OpenShift scheduling and available resources.

As of version 4.2 GA, installation is supported only on existing Red Hat OpenShift Container Platform nodes. See Deploying OpenShift Container Storage for more information.

4.1. Sizing and scaling recommendations

Red Hat OpenShift Container Storage 4.2 supports a minimum of 3 nodes and a maximum of 9 nodes.

Expand the cluster in sets of three nodes to ensure that your storage is replicated, and to ensure you can use at least three availability zones.

Warning

Always ensure that you have plenty of storage capacity.

If storage ever fills completely, it is not possible to add capacity or to delete or migrate content away from the storage to free up space. Completely full storage is very difficult to recover.

Capacity alerts are issued when cluster storage capacity reaches 75% (near-full) and 85% (full) of total capacity. Always address capacity warnings promptly, and review your storage regularly to ensure that you do not run out of storage space.

If you do run out of storage space completely, contact Red Hat Customer Support.