Hello,
The database upgrade is not that much diffrent in a cluster environment than in a "classical" set up.
You usually have to stop the SAP application servers ressources, and stop the monitoring of the database ressources in order not to have the database switched during the oracle upgrade.
You then perform the upgrade in a classical way.
But in order to make sure thos method would work could you please post your cluster ressources layout and your clustered FS layout also ?
Thx and Best regards,
S.SOUMAH.