Understanding Rolling Upgrades Using Batches
You can perform rolling upgrades of Oracle Grid Infrastructure in batches.
You can use root user automation to automate running the
                rootupgrade.sh script during the upgrade. When you use
                root user automation, you can divide the nodes into groups, or
            batches, and start upgrades of these batches. Between batches, you can move services
            from nodes running the previous release to the upgraded nodes, so that services are not
            affected by the upgrade. Oracle recommends that you use root
            automation, and allow the rootupgrade.sh script to stop and start
            instances automatically. You can also continue to run root scripts
            manually. 
               
When you upgrade Oracle Grid Infrastructure without using
                root user automation, you upgrade the entire cluster. You cannot
            select or de-select individual nodes for upgrade. Oracle does not support attempting to
            add additional nodes to a cluster during a rolling upgrade. Oracle recommends that you
            leave Oracle RAC instances running when upgrading Oracle Clusterware. When you start the
                root script on each node, the database instances on that node are
            shut down and then the rootupgrade.sh script starts the instances
            again. 
               
Restrictions for Selecting Nodes for Batch Upgrades
The following restrictions apply when selecting nodes in batches for upgrade:
- 
                        
                        
You can pool nodes in batches for upgrade, up to a maximum of three batches.
 - 
                        
                        
The local node, where Oracle Universal Installer (OUI) is running, must be upgraded in batch one.
 
Parent topic: Upgrading Oracle Grid Infrastructure