How does netbackup choose the passive copy of the database to backup when there are multiple passive copies. I have 1 active db, 1 passive, and 1 lagged copy. I want NB to always choose passive copy and not the lagged copy. I haven't found any documentation that states how it behaves when a lagged copy is present (other than links about log truncation). I know I can set a server preference list, but I was curious as to what the default process is.
Have you looked below article yet which explains to backup passive copies of Exchange DB.
You were correct, setting "server preference list" would help you to backup passive copy of Exchange DB.