System nodes

The system runs with multiple nodes. Nodes are assigned different roles, labels, and their state might change.

Physical nodes are contained in enclosures, hence their location in the system is presented as enclosureX.nodeY. The system can be configured with one node size (large) that has 64 TB of raw storage. Each enclosure contains four nodes of the same size. If you buy the base Lenovo system, it contains two enclosures, four nodes each.

Three nodes in a system are always assigned a control role and these three nodes are designated as a Control Plane. Another three nodes are assigned a worker role and they are used to run the services in your cluster. The remaining two nodes in the base system do not have any role assigned by default.

Worker nodes can also be assigned a label, which might then be used to define which service to run on a labeled node.

The combination of a role and a label is called node personality. Nodes can have the following personalities:

Table 1. Node personalities
Node personality	Description
Control Node	Three servers in a system are always assigned a control role and these three nodes are designated as a Control Plane. These servers are candidates for a Platform Manager hub. They host one Control Virtual Machine. At least two of the three control nodes must be operational for the system to work. If Netezza Performance Server (NPS) is installed on a system without connector nodes, one of the control nodes is the NPS host (`VDB master`). If NPS is installed on a system with connector nodes, the NPS host runs on a connector node.
Worker Node	Compute node for services other than NPS.
VDB Node	Compute node dedicated to NPS. Note: Nodes in this role are monitored, but they cannot be managed by Platform Manager, hence their state is always UNMANAGED. Any hardware issues are reported as in the case of the other node types.
Unset Node	A node with no personality assigned.
Connector Node (CN)	A distinct type of node that provides the ability to use fibre channel (FC) block storage for high-speed backup and restore, load, and unload for Netezza Performance Server.

Nodes are monitored by Platform Manager, which informs you of the state that the node is in. Node state can be changed manually, or automatically by Platform Manager.

The nodes are named after their enclosure and index. The first four nodes are e1n1, e1n2, e1n3, and e1n4. The second enclosure contains the next four nodes: e2n1, e2n2, e2n3, and e2n4. The index portion of the node names are always relative to their enclosure.

You can use the ap node command to view information about the nodes in your system, manage the node states, and assign personalities.