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Remove PowerHA SystemMirror Cluster Configuration and Rebuild it Again

How To


Summary

This is a guide on how to remove an old PowerHA SystemMirror cluster and rebuild it again. This guide can be useful particularly for moving a standard cluster to a linked cluster where sites need to be configured.

Objective

Removing PowerHA SystemMirror and CAA (Cluster Aware AIX) off all cluster nodes and rebuild it again from the scratch.

Environment

PowerHA SystemMirror for AIX version 7.1 and later.

Steps

A. Create cluster snapshot (optional)
# smit cm_add_snap.dialog
   Provide a name and description. The default option can be used.
1. Delete PowerHA cluster (from one node)
# smit sysmirror > Remove cluster (smitty cm_remove_cluster)
   Remove definition from all nodes [Yes]
2. Delete CAA cluster (on both nodes but one node at a time!)
# export CAA_FORCE_ENABLED=1
# rmcluster -f -r <repository_hdisk#>
Note: Expect some error messages on the second node.
# lsdev | grep cluster0
# rmdev -dl cluster0
3. complete standard CAA repository disk scrub process for both nodes:
On node1:
# export CAA_FORCE_ENABLED=1
# rmcluster -f -r <repository_hdisk#>
# rmdev -dl cluster0
# exportvg caavg_private
# chpv -c <repository_hdisk#>
# mkvg -fy vgtest <repository_hdisk#>
# reducevg -df vgtest <repository_hdisk#>
# shutdown -Fr

On node2:
# export CAA_FORCE_ENABLED=1
# rmcluster -f -r <repository_hdisk#>
# rmdev -dl cluster0
# exportvg caavg_private
# chdev -l <repository_hdisk#> -a pv=yes
# shutdown -Fr
4. Ensure Peer Domain is removed on both nodes
# /usr/sbin/rsct/bin/lsrpdomain => It should return nothing
5. Reboot both nodes
6. Initial config of the cluster (PowerHA and CAA)
# Smit sysmirror > Cluster Nodes and Networks > Standard Cluster Deployment > Initial cluster setup (Typical/Custom)
a) Using the standard configuration to create the cluster:
> Setup a Cluster, Nodes, and Networks
     This step will discover the local node and you can add the remote node:
     Cluster Name [cluster_87]
     New Nodes (via selected communication paths) []
     Currently configured Node(s) node_01
b) Define the repository.
     Define Repository Disk and Cluster IP address
     Choose a disk that is blank and that both nodes can access.
Optional: configure the Cluster IP address (multicast IP).
Thereafter sync & verify the cluster will propagate the cluster configuration to the other node and create the CAA cluster.
7. Check that cthags is running (both nodes)
# lssrc -a | grep cthags
   If it is not active, reboot the nodes
8. Start PowerHA cluster services
9. Further configurations (resources, applications, etc).
10. Sync & verify the cluster

Document Location

Worldwide

[{"Type":"SW","Line of Business":{"code":"LOB08","label":"Cognitive Systems"},"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSPHQG","label":"PowerHA SystemMirror"},"ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.1.0;and future releases"}]

Document Information

Modified date:
01 May 2021

UID

ibm16449214