Downgrading Oracle Grid Infrastructure

Use this procedure to downgrade Oracle Grid Infrastructure after a successful upgrade.

1. As the root user, use the command syntax rootcrs.sh -downgrade from 23ai Grid home to downgrade Oracle Grid Infrastructure on all nodes, in any sequence. For example:

   # $ORACLE_HOME/crs/install/rootcrs.sh -downgrade

   Run this command from a directory that has write permissions for the Oracle Grid Infrastructure installation user. You can run the downgrade script in parallel on all cluster nodes, but one.

2. Downgrade the last node after you downgrade all other nodes:

   # $ORACLE_HOME/crs/install/rootcrs.sh -downgrade

3. Set previous release Grid home as the active Oracle Clusterware home:

   1. On any of the cluster member nodes where the rootupgrade script has run successfully, log in as the Oracle Grid Infrastructure installation owner.

   2. Use the following command to start the installer, where the path you provide for ORACLE_HOME is the location of the home directory from the earlier Oracle Clusterware installation.

      $ cd $ORACLE_HOME/oui/bin 
      $ ./runInstaller -nowait -waitforcompletion -ignoreSysPrereqs 
      -updateNodeList -silent CRS=true 
      ORACLE_HOME=pre-upgrade-grid-home
      "CLUSTER_NODES=node1,node2,node3"

   pre-upgrade-grid-home is the previous release Grid home.

4. As the root user, start the Oracle Clusterware stack on all nodes from previous release Grid home.

   # crsctl start crs