Step By Step How To delete a RAC Node from 19c Cluster

Scope: In this post, I'll go you through the steps of how to remove a node in a 19c RAC cluster.
In this demo:
clsn2 will refer to the node name to be deleted from the cluster in this demo.
orcl   will refer to the cluster database name.
orcl2 will refer to the DB instance name on the node to be deleted.

Step 1: Shutdown all DB Instances running on the node to be deleted:

# srvctl stop instance -db orcl -i orcl2 -o abort

Step 2: Delete all DB Instance on the node to be deleted:

Note: This will delete the instance, remove it's REDOLOG thread and remove its UNDO tablespace as well:

# dbca -silent -ignorePrereqFailure -deleteInstance -gdbName orcl  -instanceName orcl2   -sysDBAUserName sys -sysDBAPassword oracle#123#

-gdbName            Provide the same value in DB_UNIQUE_NAME
-instanceName     The name of the instance on the node to be deleted

Step 3: Unpin the Node to be deleted:

- Check if the node you want to remove is pinned: [As root - On the node to be deleted]

# olsnodes -s -t

- If the node is pinned, then unpin it: [As root - On the node to be deleted]

# crsctl unpin css -n clsn2
 

Step 4: Deinstall GRID Home: [As GRID HOME owner - On the node to be deleted]

# $GRID_HOME/deinstall/deinstall
 

Step 5: Remove the Node from the cluster: [As root - On any of other node in the cluster]

# $GRID_HOME/bin/crsctl delete node -n clsn2

- Verify the Node deletion: [As GRID HOME owner - On any of other node in the cluster]

# $GRID_HOME/bin/cluvfy stage -post nodedel -n node_list -verbose

    Verifying Node Removal ...
      Verifying CRS Integrity ...PASSED
      Verifying Clusterware Version Consistency ...PASSED
    Verifying Node Removal ...PASSED

Post-check for node removal was successful.

Step 6: Delete the VIP Name:

- Get the VIP name of the deleted Node: [As GRID owner - On any of other node in the cluster]

# $GRID_HOME/bin/srvctl config vip -node clsn2 | grep 'Name' 

VIP Name: clsn2-vip

- Delete the VIP name of the deleted node using the VIP name output from previous command: [As root - On any of other node in the cluster]

# $GRID_HOME/bin/srvctl stop   vip  -vip clsn2-vip
# $GRID_HOME/bin/srvctl remove vip  -vip clsn2-vip -noprompt

References:

https://docs.oracle.com/en/database/oracle/oracle-database/19/cwadd/adding-and-deleting-cluster-nodes.html#GUID-8ADA9667-EC27-4EF9-9F34-C8F65A757F2A