DELETING NODE FROM CLUSTER ON A RAC 11R2

                                      In this Article I am elaborating how to delete the node from cluster (RAC).

As a DBA many times we may come across a situation that we have to delete one or multiple nodes from the cluster for various reasons.

To demonstrate, I have performing activity in configuration of 2 node RAC, where my requirement is to remove the first node from the Cluster.

      I.            Prep-Checks – (To be performed before deleting the node).

1.      Check the node name

grid@node-1:/oracle/grid/product/11.2.0/grid$ olsnodes

node-1

node-2

2.      Check the VIP of nodes

grid@node-1:/oracle/grid/product/11.2.0/grid$ olsnodes -i

node-1       node-1-vip

node-2       node-2-vip

3.      Check the Cluster Name

oracle@node-1:~$ cd /oracle/grid/product/11.2.0/grid/bin

oracle@node-1:/oracle/grid/product/11.2.0/grid/bin$ ./cemutlo -n

accupdb-cluster

  

To delete a NODE (node-1) from a cluster

1.      Ensure that Grid_home correctly specifies the full directory path for the Oracle Cluster-ware home on each node, where Grid_home is the location of the installed Oracle Cluster-ware software.

2.      Run the following command as either root or the user that installed Oracle Cluster-ware to determine whether the node you want to delete is active and whether it is pinned

$ olsnodes -s –t

root@node-1:~# . oraenv

ORACLE_SID = [SID] ? +ASM1

The Oracle base has been changed from /oracle/app/oracle to /oracle/app/grid

root@node-1:~# olsnodes -s -t

node-1       Active  Unpinned

node-2       Active  Unpinned

(If the node is pinned, then run the crsctl unpin css command. Otherwise, proceed to the next step.)

3.      From any node that you are not deleting(node-2), run the following command from the Grid_home/bin directory as root to delete the node from the cluster

                    # crsctl delete node -n node-1

4.      On the node you want to delete(node-1), run the following command as the user that installed Oracle Cluster-ware from the Grid_home/oui/bin directory where node-1  is the name of the node that you are deleting

               $ cd /oracle/grid/product/11.2.0/grid /oui/bin




$ ./runInstaller -updateNodeList ORACLE_HOME= /oracle/grid/product/11.2.0/grid "CLUSTER_NODES=

                    {node-1}" CRS=TRUE -silent –local

5.      De-install the Oracle Cluster-ware home from the node that you want to delete(node-1), as follows, by running the following command, where Grid_home  is the path defined for the Oracle Cluster-ware home

                    $ Grid_home/deinstall/deinstall –local

(Note: If you do not specify the -local flag, then the command removes the Grid Infrastructure home from every node in the cluster.)

6.      On any node other than the node you are deleting(node-2), run the following command from the Grid_home/oui/bin directory where node-2 is a comma-delimited list of the nodes that are going to remain part of your cluster

$ ./runInstaller -updateNodeList ORACLE_HOME= /oracle/grid/product/11.2.0/grid "CLUSTER_NODES=

                    {node-2}" CRS=TRUE –silent

7.      Run this command a second time where ORACLE_HOME=ORACLE_HOME, and CRS=TRUE -silent is omitted from the syntax, as follows

$ ./runInstaller -updateNodeList ORACLE_HOME= /oracle/app/oracle/product/11.2.0/db_1

                    "CLUSTER_NODES= {node-2}"

8.      Run the following CVU command to verify that the specified nodes have been successfully deleted from the cluster.

                    $ cluvfy stage -post nodedel -n node_list [-verbose]

                                                                          There you good to go.................................................




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