Immediately after I get home from your wedding, and before I have a date with a bottle of wine and a bubble bath, I backup the images to two different external hard drives. One of those hard drives goes directly into a safe and the other lives on my desk. I also have a specific portable hard drive that I use for travel weddings and the images get backed up on to my laptop hard drive as well as a portable hard drive, then backed up again to my primary hard drives when I return home. I do not erase/format any of my or my second photographer's camera cards until your wedding images are edited and delivered. I do not delete edited + delivered images from any events and I keep a backup of RAW images for at least 2 years.