The article describes how to properly perform maintenance of the POA Management Node that resides on PVC (Parallels Virtuozzo Container) for Linux cluster.
If maintenance requires to shutdown the clustered nodes, then simple node shutdown can cause losing Quorum, as the result cluster will try to fence another nodes - that is not a good situation.
The proper way to perform maintenace of the clustered POA Management Node would be as follows.
- Stop all clustered services
Make all nodes to leave cluster using the 'cman' utility:
# /etc/init.d/cman stop leave
Shutdown clustered nodes
- Perform the required maintenance
- Bring nodes up
- Join all nodes to cluster by starting the 'cman' service
You may perform the actions above from the LUCI Conga interface (the cluster management tool in RHEL6), or using the 'system-config-cluster' tool in case of RHEL5.