How to rename the Hostname in an Oracle RAC Cluster

Renaming a hostname in an Oracle Real Application Clusters (RAC) environment requires careful execution to ensure database continuity. This guide demonstrates how to rename the hostname in a two-node RAC cluster (devdb-01, devdb-02) by modifying devdb-01 to devdb-new-01.

• RAC User = DB HOME Owner

• GI User = GI HOME Owner or root

Step 1: Remove the DB Instance from the Old Node

On devdb-01, connect as the RAC user and remove the running database instance:

a. srvctl disable instance -db <db_unique_name> -instance <inst_name>
b. srvctl stop instance -db <db_unique_name> {-node <old_node_name> | -instance <inst_name>} -stopoption NORMAL -failover
c. srvctl remove instance -db <db_unique_name> -instance <inst_name> -force

Step 2: Deconfigure Oracle Clusterware on the Old Node

On devdb-01, connect as the root user and execute:

$GI_HOME/crs/install/rootcrs.sh -deconfig -force

Step 3: Remove the Node from the Cluster

On devdb-02, connect as the root user and run:

Syntax:

$GI_HOME/bin/crsctl delete node -n <Node1>

Example:

$GI_HOME/bin/crsctl delete node -n devdb-01

Step 4: Rename the Host

On devdb-01, connect as the root user and modify the hostname using the standard procedure for your OS.

Step 5: Add the Node with the New Hostname

On devdb-01, connect as the Grid user and execute the following command:

Syntax:

$GI_HOME/addnode/addnode.sh -silent -noCopy "CLUSTER_NEW_NODES=<N1>" "CLUSTER_NEW_VIRTUAL_HOSTNAMES=<N1-vip>" "CLUSTER_NEW_NODE_ROLES=hub"

Example:

$GI_HOME/addnode/addnode.sh -silent -noCopy "CLUSTER_NEW_NODES=devdb-new-01" "CLUSTER_NEW_VIRTUAL_HOSTNAMES=devdb-new-01-vip" "CLUSTER_NEW_NODE_ROLES=hub"

Step 6: Run the Root Script

On devdb-new-01, connect as the root user and execute:

$GI_HOME/root.sh  # This may take around 5 minutes

Step 7: Recreate the DB Instance on the Renamed Node

On devdb-new-01, connect as the RAC user and create a new database instance:

Syntax:

srvctl add instance -db <db_unique_name> -instance <inst_name> -node <new_node_name>

Example:

srvctl add instance -db <db_unique_name> -instance <inst_name> -node devdb-new-01

Following these steps ensures a smooth hostname transition in an Oracle RAC environment, maintaining high availability and minimal downtime. Always verify the changes before proceeding with production deployments.