SAP HANA nodes can be expanded in the scale-up or scale-out mode.
Also called single-node system mode, in which an SAP HANA system contains only one valid node. If high availability (HA) is required, construct such architecture using two single nodes through System Replication. This system architecture supports only scale-up expansion. In this mode, add CPUs, memory capacity, and hard disks to the node.
The system does not support expansion for a node on which SAP HANA is running.
Also called cluster system mode, in which an SAP HANA system contains multiple nodes. In scale-out mode, when the system requires expansion, add more nodes to the system.