Add or replace nodes

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After you install, configure PowerVC operations manager (OpsMgr) and successfully install PowerVC on single node, you can choose to move to multinode. You can also choose to replace one of the nodes in the cluster with another node.

This topic explains the procedure for adding or replacing a node.
Notes:
  • Legacy install of PowerVC is not supported for add node, replace node, resync node, and compute plane node registration.
  • If LDAP is already configured before adding or replacing nodes, you must reconfigure LDAP after performing the add or replace node operation.
  • When adding or replacing a node, make sure that the NTP is active and the time is in sync on all nodes before you perform operations such as install, add node, or replace node and prevent any issues related to host or VM deployment.
  • Make sure you disable IPv6 before proceeding with install procedure. For details, see Disable IPv6 topic.
  • Restore operation is supported only on a single or a three node cluster. After upgrading to PowerVC 2.1.1, you can add two more nodes to convert a cluster into three node cluster. Later, you can add two more nodes to convert a three node cluster to a five node cluster. You can take a backup of five node cluster and restore the same on a three node cluster.
  • Registration or deregistration of a host, storage, or a fabric is supported even when a node goes down. After the node is up, you can run powervc-opsmgr resync_node -s <source_host> -d <dest_host> to sync the conf files on the source host and destination host.

Add nodes

Prerequisite

You must provide two more nodes that are identical to the existing node that is, the nodes must have same distro or version. Starting 2.1.0 release, PowerVC supports 5 node control plane cluster.

If it is SLES nodes, run these commands to enable the network and network_utilities repos on the two new nodes before running setup_opsmgr.sh for installing PowerVC 2.1.1 or running update_opsmgr.sh for updating to PowerVC 2.1.1.
  • zypper ar -G https://download.opensuse.org/repositories/network/<SLE_15/ network>
  • zypper ar -G https://download.opensuse.org/repositories/network:/utilities/<SLE_15/ network_utilities>

Run powervc-opsmgr addnodes -c <cluster name> -s to add nodes. This converts single node setup to multinode. The command captures IP addresses of new nodes and updates inventory for the cluster. PowerVC can be installed on new nodes.

After installing OpsMgr and creating a cluster, you can install PowerVC on single node and later add multiple nodes (up to three nodes). For more details about subcommands, run powervc-opsmgr addnodes -h.
Note: In this command powervc-opsmgr addnodes -c <cluster name> -s, -s option is needed if systems are registered with RHN repo. Before you add nodes, if the initial system is registered with RHN, make sure that the other systems are also registered with RHN. Also, make sure to install net-tools and rsync packages on newly added nodes.

Example:

 
[root@vm-2253 ~]# powervc-opsmgr addnodes  -c <cluster_name> -s
*********************************************************
INFO: Adding Nodes to PowerVC. Provide info for 2 Nodes 
to be added.
*********************************************************
Enter IP/Hostname for Add Node 1: 9.x.x.x
Enter Username for Add Node 1: root
Enter Password for Add Node 1: 
*********************************************************
Enter IP/Hostname for Add Node 2: 9.x.x.x
Enter Username for Add Node 2: root
Enter Password for Add Node 2:
Establishing passwordless connection
Upon addition of nodes, you can access nodes via virtual IP.

Replace a node

Prerequisite

You must provide details of the node that must be removed and the node to be added. The new node must have same distro or version.

Run powervc-opsmgr replacenode -c <cluster name> -s to replace a node. The command captures IP addresses of the node to be removed and the new node to be added. Later, the node is removed from the cluster and the new node is added to the cluster. Upon addition of the new node, the command uninstalls the removed node for future use if it is accessible. For more details about subcommands, run powervc-opsmgr replacenodes -h.
Notes:
  • In this command powervc-opsmgr replacenode -c <cluster name> -s, -s option is needed if systems are registered with RHN repo. Before you replace a node, if the systems are registered with RHN, make sure that the new system is also registered with RHN.
  • If you are running replace node from a non primary / bootstrap node then perform these steps.
    1. Edit powervc/group_vars/all/mode.yml to set powervc_operation_mode.
    2. Run powervc-opsmgr replacenode command.
  • For replace node operation on SLES, transfer powervc-opsmgr installer tar file to two new nodes, extract the file, and then run setup_opsmgr.sh on all nodes.

Example:

 [root@vm-247 powervc_opsmgr]# powervc-opsmgr replacenode -c <cluster_name> -s
*********************************************************
Enter IP of the node to be replaced: 9.x.x.x
*********************************************************
INFO: Enter the IP address of the node that needs to be added
*********************************************************
Enter IP/Hostname for Add Node 1: 9.x.x.x
Enter Username for Add Node 1: root
Enter Password for Add Node 1:
Establishing passwordless connection

---
---
Passwordless connection established.
*********************************************************
Removing node 9.x.x.x from cluster <cluster_name>.
*********************************************************
---
---
Removing Node 9.x.x.x successfully completed at 2021-07-05 18:32:53.
Refer to
/opt/ibm/powervc-opsmgr/ansible/artifacts/powervc-opsmgr_<cluster_name>_remove_node_20210705_183250/stdout
for more details.
*************************************************************
Removing node is successful. Continuing with adding node.
*************************************************************
*********************************************************
Adding node 9.x.x.x to cluster <cluster_name>.
*********************************************************
---
---
Adding Node 9.x.x.x to Cluster <cluster_name> successfully completed at 2021-07-05 18:32:57.
Refer to /opt/ibm/powervc-opsmgr/ansible/artifacts/powervc-opsmgr_<cluster_name>_add_node_20210705_183253/stdout
for more details.
You can access nodes via virtual IP.