Delete a node from RAC

 To remove a node from a which is part of a RAC involves several steps

1. Stop the database and ASM on particular instance
2. Remove the database and ASM
3. Remove the Oracle Database Software
4. Remove the Clustware
5. Update the oracle inventory

Current Scenario:-

[oracle@rac1 ~]$ olsnodes -s -t
rac1 Active Unpinned
rac2 Active Unpinned
rac3 Active Unpinned

[oracle@rac1 ~]$ srvctl status database -d RAC -v
Instance RAC1 is running on node rac1. Instance status: Open.
Instance RAC2 is running on node rac2. Instance status: Open.
Instance RAC3 is running on node rac3. Instance status: Open.
[oracle@rac1 ~]$

SQL> select inst_id, instance_name, status, to_char(startup_time, 'DD-MON-YYYY HH24:MI:SS') as "START_TIME" from gv$instance order by inst_id;

INST_ID INSTANCE_NAME STATUS START_TIME
---------- ---------------- ------------ -----------------------------
1 RAC1 OPEN 16-AUG-2016 03:27:08
2 RAC2 OPEN 16-AUG-2016 03:36:37
3 RAC3 OPEN 16-AUG-2016 03:36:00

Step 1: Stop the instance

[oracle@rac1 ~]$ srvctl stop instance -d RAC -i RAC3

[oracle@rac1 ~]$ srvctl status database -d RAC
Instance RAC1 is running on node rac1
Instance RAC2 is running on node rac2
Instance RAC3 is not running on node rac3

Step 2: Remove the instance

[oracle@rac1 ~]$ srvctl remove instance -d RAC -i RAC3
Remove instance from the database RAC? (y/[n]) y
[oracle@rac1 ~]$

Step 3: Disable oracle clusterware on node 3

[root@rac3 ~]# cd /u01/app/11.2.0/grid/crs/install
[root@rac3 install]# ./rootcrs.pl -deconfig -deinstall -force

Step 4: Disable and stop the Listener on node 3

[root@rac3 ~]# srvctl stop vip -i rac3-vip -f
[root@rac3 ~]# srvctl remove vip -i rac3-vip -f

Step 5: Delete the node

Note: Run below command from surviving node

[root@rac1 bin]# pwd
/u01/app/11.2.0/grid/bin
[root@rac1 bin]# ./crsctl delete node -n rac3
CRS-4661: Node rac3 successfully deleted.
[root@rac1 bin]#

Step 6: Update the inventory for Grid Home

[root@rac1 bin]# /u01/app/11.2.0/grid/oui/bin
[root@rac1 bin]# ./runInstaller -updateNodeList ORACLE_HOME=/u01/app/11.2.0/grid "CLUSTER_NODES={rac1,rac2}" CRS=TRUE

Step 7: Remove the database home

[oracle@rac3 deinstall]$ /u01/app/oracle/product/11.2.0/dbhome_1/deinstall
[oracle@rac3 deinstall]$ ./deinstall -local

Step 8: Update the inventory for Database Home

[oracle@rac3 ~]$ /u01/app/oracle/product/11.2.0/dbhome_1/oui/bin
[oracle@rac3 ~]$ ./runInstaller -updateNodeList ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1 "CLUSTER_NODES={rac1,rac2}"

Step 9: Post Deletion Steps

rm -rf /etc/oraInst.loc
rm -rf /etc/oracle
rm -rf /opt/ORCLfmap
rm -rf /etc/oratab
rm -rf /u01
groupdel dba oinstall
rm -rf /u01/app/oracle