Become Oracle Apps DBA: Orcale RAC Part III - Clone RAC1 to RAC2 and User Equivalency

Make sure you can start both machine at same time, if you get message like unable to lock files, check you have added following lines in both machines vmx files mentioned above (regarding disk locking)

If you get error message that eth0 has different MAC address expected as shown below; make sure you have clicked on probe on “Bind to Mac Address” on “Hardware Device” mentioned above.

Make sure both network cards are active now, as shown below

Add following entry in /etc/hosts file of both RAC1 and RAC2

####

127.0.0.1 loalhost.localdomain localhost
192.168.1.102 rac2.focusthread.com rac2 rac2-vip.focusthread.com rac2-vip
192.168.0.102 rac2-priv.focusthread.com rac2-priv
192.168.1.101 rac1.focusthread.com rac1 rac1-vip.focusthread.com rac1-vip
192.168.0.101 rac1-priv.focusthread.com rac1-priv

###

Now trying to ping RAC2 machine from RAC1 and RAC1 machine from RAC2

Change Host Name of newly cloned RAC2

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Follow below step on how to change hostname on RAC2 (newly cloned) Linux machine

Open file /etc/sysconfig/network and edit line like : HOSTNAME=XXXXX i.e. from

HOSTNAME rac1.focusthread.com To HOSTNAME rac2.focusthread.com

Configure User Equivalency

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User equivalency for user oracle is required so that user oracle from RAC1 can communicate to user oracle on RAC2 machine without prompting for password for clusterware to work properly.

--Login as user oracle in machine RAC1

--Make sure sshd daemon is running (pgrep sshd), If not start it from root user like “service start sshd”

--Create RSA and DSA key on each node

-From oracle user go to user home directory by “cd $HOME” or type cd and press enter
-mkdir .ssh (note that there is dot before ssh which means this is hidden directory)
-chmod 700 .ssh
-ssh-keygen –t rsa
-ssh-keygen –t dsa

press enter when prompted for file to save the key and passphrase (check screenshot for more information)

“Repeat this on both the nodes i.e. RAC1 and RAC2”

Add keys to authorized key file (authorized_keys)

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-cd .ssh

-touch authorized_keys
-ls (You should see authorized_keys, id_dsa, id_dsa.pub, id_rsa, id_rsa.pub. Here pub files are dsa and rsa public key file and id_dsa and id_rsa are private key files)

ssh rac1 cat /home/oracle/.ssh/id_rsa.pub >> authorized_keys
ssh rac1 cat /home/oracle/.ssh/id_dsa.pub >> authorized_keys
ssh rac2 cat /home/oracle/.ssh/id_rsa.pub >> authorized_keys
ssh rac2 cat /home/oracle/.ssh/id_dsa.pub >> authorized_keys

Send authorized_keys from RAC1 to RAC2

scp authorized_keys rac2:/home/oracle/.ssh

From RAC1 machine as user oracle
exec /usr/bin/ssh-agent $SHELL
/usr/bin/ssh-add

Test User Equivalency (User oracle can login to other machine without password prompt)

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ssh rac1 date

ssh rac2 date

Test this from both nodes RAC1 and RAC2 (You should not be prompted for oracle user password)

For more information on User Equivalency visit chapter 2 (Page 51 to 53) of clusterware and rac installation guide

Coming Next :

Installing clusterware on RAC1 and RAC2

Installing RAC database on RAC1 and RAC2 linux machines using ASM

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