Chapter 6. Maintenance procedures
6.1. Update RHEL and the RHEL HA Add-On
Please refer to Recommendations: Applying package updates in a RHEL High Availability cluster, for more information.
For two-node cluster setups it is not necessary to manually move the resources to the other HA cluster node before placing the HA cluster node in standby mode (putting the HA cluster node in standby mode will take care of moving or stopping the resources running on the HA cluster node based on the HA cluster configuration).
Also, to minimize downtime of the SAP system it is recommended to first update the HA cluster node running the “less critical” resources, like the ERS instance. When the HA cluster node has been updated and it has been verified that the resources that were running on the node before the update was started are running again, the other HA cluster node running the “critical” resources, like the (A)SCS instance, can be updated as well.
