We have to rebuilt/duplicate all databases on standby RAC servers, in the step when i was adding standby logfile i received error "ORA-01156" it was too annoying, on top of that i was terribly tired with that RMAN backup crash for one of the database at Production Site, so you can imagine, i had to solve two problems at the same time on two different sites :-S
anyhow i found a very nice post on ORA-01156 as a matter of fact the post was so concise that i took 2 minutes to solve it !
look at the beauty of the post ! just few lines and problem explained with solution.
i ran just following lines in my case and solved it !
Why is this happening?
You cannot add standby redo log while the database is in managed recovery mode.
How do I fix it?
Exit managed recovery mode, add the logs, and then reinitiate managed recovery:
alter database recover managed standby database cancel;
alter database add standby logfile group
alter database recover managed standby database disconnect;