The Oracle 9 to 10GR2 upgrade that I completed last week will be getting its final test on Sunday. We will be failing over to our standby server and see what happens. I am not worried about this as all the files that are associated with the upgrade are on disk that is shared between the two cluster nodes. The only exception is in /var/opt/oracle and I have modified those files to be what they need to be. Keep your fingers crossed for me but I think I am in good shape.