RAC conversion

 

Setting up a second node in an Oracle RAC (Real Application Clusters) environment requires careful configuration to ensure consistency across nodes. This guide walks you through enabling RAC in an existing Oracle Home and configuring the second instance properly. 

 

1. Relink library binaries to enable RAC on a particular Oracle Home 

 

cd $ORACLE_HOME/rdbms/lib

make -f ins_rdbms.mk rac_on
make -f ins_rdbms.mk ipc_rds ioracle

2. Configure system parameters 

 

a. Using spfile(Recommended) 

 

Connect as sysdba and run 

 

ALTER SYSTEM SET instance_name=DBNAME2 SCOPE=SPFILE SID='DBNAME2';
ALTER SYSTEM SET instance_number=2 SCOPE=SPFILE SID='DBNAME2';
ALTER SYSTEM SET thread=2 SCOPE=SPFILE SID='DBNAME2';

b. Using pfile

 Add the following entries

 

DBNAME1.instance_number=1
DBNAME2.instance_number=2

DBNAME1.local_listener='node1-hostname:port'
DBNAME2.local_listener='node2-hostname:port'

DBNAME1.thread=1
DBNAME2.thread=2

DBNAME1.undo_tablespace='UNDOTBS1'
DBNAME2.undo_tablespace='UNDOTBS2'

3. Add redo logs and UNDO Tablespace for Node2 --- Create only if not present 

ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 1 SIZE <size>;
ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 2 SIZE <size>;

CREATE UNDO TABLESPACE UNDOTBS2 DATAFILE '+DATAC1' SIZE <size>;

4. Add database and instances to the Cluster

Using srvctl to register the database and instances with the cluster. 

srvctl add database -d DBNAME -o <ORACLE_HOME>

srvctl add instance -d DBNAME -i DBNAME1 -n node1-hostname
srvctl add instance -d DBNAME -i DBNAME2 -n node2-hostname

srvctl setenv database -d DBNAME -T TNS_ADMIN=$ORACLE_HOME/network/admin/DBNAME
srvctl getenv database -d DBNAME

5. Move SPFILE to ASM Diskgroup  

create spfile='+DATAC1/spfileDBNAME.ora' from pfile;

• Add the above entry in initDBNAME1.ora under $ORACLE_HOME/dbs

• Copy the initDBNAME1.ora file from Node1 to Node2 as initDBNAME2.ora

cat initDBNAME1.ora
spfile='+DATAC1/spfileDBNAME.ora' 

6. Copy Required Network and Security Files to Node2

Copy the following from Node1 to Node2:

• tnsnames.ora 
• sqlnet.ora
• Password file
• Wallet files (if used)

Make necessary hostname adjustments where required. 

7. Start the Database Using srvctl

Finally, start the database: 

 

srvctl start database -d DBNAME

srvctl status database -d DBNAME