Creating New 11gr2 database on existing 11gr2 RAC

It is assumed that 11gr2 cluster has been installed. ASM is configured and disks are prepared for new database.

1-) Create new OS user for new database. New user should be in the same group with grid's OS user (Using different os users for databases is optional, not a must)

2-) Set ssh trust between the nodes for the newly created os user:

From each node, logged in as new user:


mkdir ~/.ssh
chmod 755 ~/.ssh
/usr/bin/ssh-keygen -t rsa
/usr/bin/ssh-keygen -t dsa

Example:
$ mkdir ~/.ssh
$ chmod 755 ~/.ssh
$ /usr/bin/ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (.../.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:

Your identification has been saved in .../.ssh/id_rsa.
Your public key has been saved in .../.ssh/id_rsa.pub.
The key fingerprint is:
XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX os_user@my.domain.com

$ /usr/bin/ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (.../.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:

Your identification has been saved in .../.ssh/id_dsa.
Your public key has been saved in .../.ssh/id_dsa.pub.
 The key fingerprint is:
XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX os_user@my.domain.com

Append all public keys to authorized_keys of all nodes:

FIRST NODE

cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
ssh os_user@node2 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
ssh os_user@node2 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
chmod 644 ~/.ssh/authorized_keys

SECOND NODE

cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
ssh os_user@node1 cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
ssh os_user@node1 cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
chmod 644 ~/.ssh/authorized_keys

ssh command run at previous step will register each node's ssh identity to the known_hosts file at other node (confirmation appeared when you run ssh first). However, every node should also has a know_hosts entry for itself. In order to do that, run following command at each node and answer yes at confirmation.

ssh os_user@nodeitself ls

Finally, check that each node does a ssh ls to orher node without requiring any password or confirmation.

ssh os_user@othernode ls
ssh os_user@nodeitself ls


3-) edit user profile and set following variables:
 
ORACLE_HOME

RDBMS_HOME
ASM_HOME
CRS_HOME
ORACLE_BASE
PATH
ORACLE_SID
LD_LIBRARY_PATH
4-) Check permisions of ORACLE HOME and BASE so new user has write permission on these (on both nodes)
5-) Set new environments paramaters on both nodes.
6-) Start Installer and install software only... Create database? maybe next time...