Depending on the model of the storage system, an HA pair can consist of two controllers in a single chassis, or two controllers in two separate chassis. Some models can be configured either way, while other models can be configured only as a single-chassis HA pair or dual-chassis HA pair.
The following example shows a single-chassis HA pair:
In a single-chassis HA pair, both controllers are in the same chassis. The HA interconnect is provided by the internal backplane. No external HA interconnect cabling is required.
The following example shows a dual-chassis HA pair and the HA interconnect cables:
In a dual-chassis HA pair, the controllers are in separate chassis. The HA interconnect is provided by external cabling.