Adding a node to increase the size of a cluster using the CLI

You can use the command-line interface (CLI) to increase the size of a cluster by adding two nodes to create a new I/O group.

Attention: If you are adding a node that was previously removed from a cluster, ensure that either the following two conditions have been met:

The WWPN for the removed node is swapped with the node that replaces it.
All hosts that accessed the removed node through its WWPNs have been reconfigured to use the WWPN for the new node.

Failure to do either of these action can result in data corruption.

Complete the following steps to add a node and increase the size of a cluster:

Install the new nodes and connect to the fibre channel.
Issue the following command to verify that the node is detected on the fabric:
```
svcinfo lsnodecandidate
```
Using the front panel of the node, record the WWNN.
Issue the following command to determine the I/O group where the node should be added:
```
svcinfo lsiogrp
```
Record the name or ID of the first I/O group that has a node count of zero (0). You will need the ID for the next step.
Note: You only need to do this step for the first node that is added. The second node of the pair uses the same I/O group number.
Record the following information for future reference:
- Node serial number.
- Worldwide node name.
- All of the worldwide port names.
- The name or ID of the I/O group that contains the node.
Issue the following command to add the node to the cluster:
```
svctask addnode  -wwnodename WWNN -iogrp newiogrpname/id  [-name newnodename]
```
Where WWNN is the WWNN of the node, newiogrpname/id is the name or ID of the I/O group that you want to add the node to and newnodename is the name that you want to assign to the node. If you do not specify a new node name, a default name is assigned; however, it is recommended you specify a meaningful name.
Record the following information for future reference:
- Node serial number.
- Worldwide node name.
- All of the worldwide port names.
- The name or ID of the I/O group that contains the node.
Issue the following command to verify that the node is online:
```
svcinfo lsnode
```

You may need to reconfigure your storage systems to allow the new I/O group nodes to access them. If the disk controller uses mapping to present RAID arrays or partitions to the cluster and the WWNNs or the worldwide port names have changed, you must modify the port groups that belong to the cluster.