Live / Live
Please go away and learn how to set up proper IT systems
I'm always amazed at the "IT Specialists" who make stupid comments on here about DR plans, backups, AV , etc. There are BIG organisations out there who know FAR more about running these services than your piddly little IT group that supports 20 servers and 300 users.
I think you'll find most of the really critical services run live/live out of multiple locations, so a DR plan typically doesn't have a big red invoke button, but simply a "let's recover that bit that's failed in a controlled manner while the rest of the system picks up the load" - and yes, that plan is written, and tested twice a year as part of their license from the FSA.
Enterprise IT is pretty good at making sure the infrastructrure works, and since banks have been amongst the biggest users of IT for nearly the longest time, they generally have all the bases covered (yes, yes, occasionally some Business idiot manages to squeeze in some "service" that doesn't work properly)