Adding a node to a cluster

You can use the clmgr command to dynamically add a node to an existing cluster.

Consider a scenario in which you are creating a cluster that is named clMain, and if the participating nodes are nodeA and nodeB, enter the following command to add these nodes to the clMain cluster:

clmgr create cluster clMain NODES=nodeA,nodeB

start of changeBy default, the value of the START_ON_BOOT parameter for nodeA and nodeB is FALSE. If the value of the START_ON_BOOT parameter is TRUE, the cluster services on a node are always brought online automatically and the value of STATE parameter in the query node is set to ONLINE after the system reboot. If the value of the START_ON_BOOT parameter is FALSE, you must manually bring the cluster services online on a node after the system reboot. The value of the STATE parameter in the query node is set to OFFLINE after the system reboot.end of change

After you create the clMain cluster with nodeA and nodeB, you can also add nodeC to the clMain cluster by running the following command:
clmgr add node nodeC
start of changeBy default, the value of the START_ON_BOOT parameter for nodeC is FALSE. You can set the value of the START_ON_BOOT parameter to TRUE when you add nodeC to the clMain cluster by running the following command:
clmgr add node nodeC START_ON_BOOT=TRUE
You can change the configured value of the START_ON_BOOT parameter on the existing node. If you want to change the value of the START_ON_BOOT parameter to TRUE, run the following command:
clmgr online node nodeC when=reboot
The clmgr online node command includes the following attributes:
MANAGE
You can set the value of this attribute to auto or manual. When you set the value of this attribute to auto, the clmgr command automatically brings the resource group online on bringing the cluster node online. When you set the value of this attribute to manual, you must manually bring the resource groups online. The default value of the MANAGE attribute is auto.
WHEN
You can set this attribute to one of the following values:
  • now: The clmgr command brings the cluster node online instantly and the value of the START_ON_BOOT parameter remains unchanged.
  • reboot: The clmgr command brings the cluster node online after the system reboot and the value of the START_ON_BOOT parameter is set to TRUE.
  • both: The clmgr command brings the cluster node online instantly and the value of the START_ON_BOOT parameter is set to TRUE after the system reboot.
You can change the configured value of the START_ON_BOOT parameter to FALSE by running the following command:
clmgr offline node nodeC when=reboot
The clmgr offline node command includes the following attributes:
MANAGE
You can set the value of this attribute to offline or move. When you set the value of this attribute to offline, the clmgr command automatically brings the resource groups on that node to an offline state before it brings the node to an offline state. When you set value of this attribute to move, the clmgr command moves the resource groups from that node to other node as specified in resource group policies before the cluster node are brought to an offline state. The default value of the manage attribute is offline.
STOP_RSCT
You can set this attribute to one of the following values:
  • yes: The clmgr command stops the RSCT peer domain cluster on the cluster node. The value of the RSCT_CLUSTER_STATE parameter is set to OFFLINE in the query node.
  • no: The RSCT peer domain cluster remains online on the cluster node, but the node cannot host any resource groups. The value of the RSCT_CLUSTER_STATE parameter is ONLINE but the value of the STATE parameter is OFFLINE in the query node.

The default value of the STOP_RSCT parameter is no. The value of the STOP_RSCT attribute is set to yes during PowerHA® SystemMirror® for Linux migration operations.

WHEN
You can set this attribute to one of the following values:
  • now: The clmgr command brings the cluster node to an offline state instantly and the value of the START_ON_BOOT parameter remains unchanged.
  • reboot: The clmgr command brings the cluster node to an offline state after system reboot and the value of the START_ON_BOOT parameter is set to FALSE.
  • both: The clmgr command brings the cluster node to an offline state instantly and the value of the START_ON_BOOT parameter is set to FALSE after the system reboot.
end of change