Add a 3rd node to Oracle RAC 11gr2

1 Verify the prerequisites with cluvfy
 

Login as a grid user on one of the existing cluster nodes, for example raclinux1, and run the following commands.
 

cluvfy stage -post hwos -n rac3

cluvfy comp peer -refnode rac1 -n rac3

cluvfy stage -pre nodeadd -n rac3

cluvfy stage -pre crsinst -n rac3


2 Ignore error due to Bug #10310848 
If your shared storage is ASM using asmlib you may get an error – similar to the following 
 
ERROR:
PRVF-5449 : Check of Voting Disk location "ORCL:CRS1(ORCL:CRS1)" failed on the following nodes:

        rac3:No such file or directory

PRVF-5431 : Oracle Cluster Voting Disk configuration check failed

To ignore it:

IGNORE_PREADDNODE_CHECKS=Y 
export IGNORE_PREADDNODE_CHECKS

3 Extend Clusterware
addNode.sh "CLUSTER_NEW_NODES={rac3}" "CLUSTER_NEW_VIRTUAL_HOSTNAMES={rac3-vip}"

execute following as root on new node:
/u01/app/oraInventory/orainstRoot.sh
/u01/app/crs/11.2.0,2/root.sh

verify new node:
cluvfy stage -post crsinst -n rac3-lnx
cluvfy stage -post nodeadd -n rac3-lnx  

4 Extend Oracle Database Software

$ORACLE_HOME/oui/bin/addNode.sh -silent "CLUSTER_NEW_NODES={rac3}"

5 Use DBCA to add database instance on new nodes