Advise on OS patch upgrade with RAC

Customer is running 10.2.0.2 RAC on Solaris 10. Final objective is to upgrade to RAC 10.2.0.4. Requirement is as below;

1) Upgrade Solaris 10 patches from Generic_118833-03 to 142909-17
2) Upgrade RAC to 10.2.0.4

Question1:
Customer is thinking of performing the OS patch upgrade via the below strategy;

Night1:
1. Shutdown node2.
2. Shutdown crs/db on node1.
3. Perform OS upgrade on node1.
4. Once node1 successfully upgrade it’s OS, start crs/db on node1 and continue database operation until night2. Take note that node2 is down from night1 until night2.

Night2:
1. Shutdown node1.
2. Startup node2; do not startup node2 crs/db.
3. Perform OS upgrade of node2.
4. Once node2 successfully upgrade it’s OS, startup crs/db on node2.
5. Now startup node1 and it’s crs/db and join cluster
Now both node crs/db continues operation.

Is there any concern on the OS patch upgrade strategy as above?

A: No issue on the OS patch upgarde. Stay within a 24 hours of upgrade window.

Question2: After the OS patch upgrade via the strategy above, is there a need to do anything on rac (db/crs)? Perhaps relink? Or do we just bring up crs and both crs/db will up and running?

A: Doc ID 444595.1 – Is It Necessary To Relink Oracle Following OS Upgrade?

Question3: We notice that SUNWsprox OS package is not available in both servers. However RAC is already up and running. Does it mean that SUNWsprox package is not needed in SOlaris 10?

A: That OS-Package SUNWsprox is not required at Solaris 10 (see note 169706.1). Therefore this error can be ignored on your OS version.

Question4: Customer would like to disable gsd. Is this recommended?

A: Yes you can disable the gsd.

Question5: During the OS patch upgrade, java version will be upgraded from “1.5.0_06” to “1.5.0_24”. Will there be any issue with RAC?

A: No issue with RAC.

Question6: If OS patch in node1 is upgraded but not on node2, will RAC have any issue?

A: Please refer the below doc,

Doc ID 220970.1 – RAC: Frequently Asked Questions