Performing planned maintenance

The cluster connector is designed to integrate the cluster with SAP start framework (sapstartsrv), including the rolling kernel switch (RKS) awareness. Stopping and starting the SAP system using sapcontrol should not result in any cluster remediation activities as these actions are not interpreted as failures. Validate this scenario when testing your cluster.

There are different options to perform planned maintenance on nodes, resources, and the cluster.

Maintenance mode

Use maintenance mode if you want to make any changes to the configuration or take control of the resources and nodes in the cluster. In most cases, this is the safest option for administrative tasks.

Placing a node in standby mode

To perform maintenance on the cluster without system outage, the recommended method for moving active resources is to place the node you want to remove from the cluster in standby mode.

# pcs node standby <hostname>

The cluster will cleanly relocate resources, and you can perform activities, including reboots on the node in standby mode. When maintenance activities are complete, you can re-introduce the node with the following command.

# pcs node unstandby <hostname>

Moving a resource

Moving individual resources is not recommended because of the migration or move constraints that are created to lock the resource in its new location. These can be cleared as described in the info messages, but this introduces an additional setup.

<rhxhost01>:~ pcs resource move grp_<RHX>_ASCS<00> <rhxhost02>
Location constraint to move resource 'grp_<RHX>_ASCS<00>' has been created
Run 'pcs resource clear grp_<RHX>_ASCS<00>' to remove this constraint

Use the following command once the resources have relocated to their target location.

# pcs resource clear grp_RHX_ASCS00