Multiple racks

In high-availability multi-rack, at installation time, you can connect three IBM Storage Fusion HCI System racks to create a single large OpenShift® Container Platform cluster. The control nodes are distributed across multiple racks for fault tolerance. The Fusion Data Foundation storage spreads its resources in these three racks so that you do not lose data when a rack goes into maintenance mode. For example, a three-rack cluster can have up to 3,072 (1,024 x 3) physical cores. The multiple side-by-side (adjacent) appliances act as a single unit and hosts a single Fusion Data Foundation storage and OpenShift Container Platform cluster. To achieve high availability, 1 control node (Rack Unit 2) is available in each of these three racks so even when one rack goes down, the cluster stays available. The components in each of the three racks are the same as a single rack. For more information about component details and hardware configuration, see Hardware overview of a single rack.

• For High-availability Multi rack, order three similar racks from IBM factory. You must have 3 racks with a minimum of 6 nodes per rack.
• The three availability zone deployment of Fusion HCI involves three racks, each placed in an availability zone. Two spine switches are required to connect the three racks together. They are placed in two of the three racks, towards the top of the rack. Order two spine switches (MTM 9155-S01) from IBM and the cables to connect the racks to the spine switches. For the installation instructions of the spine switch, contact IBM Support. You must order the spine switches from IBM. You can order the cables from IBM or provide the cables. Determine the length of the required cables based on the proximity of the racks to the spine switches.
• Each rack must have the same number of storage nodes. Ensure that the number of NVMe drives are uniform across storage nodes in the multi-rack solution.