My answer to them was none. I simply backup my computer every night using Super Duper for Mac. So I not only have a backup of my computer, but also a backup of Lightroom’s catalog in the process.
After reading your comments, I’ve since changed my strategy though. See, when Lightroom backs up your catalog, it does an integrity check. Several people pointed out that they’ve had corruption problems with their catalog before. So theoretically, my backup plan could cause a problem. What if my catalog became corrupt? Then, that night I backed up to Super Duper. But instead, my backup now became the corrupt version? Now, it’s never actually happened to me. And I don’t personally know anyone who’s had a corrupt catalog either. But there were enough comments from people who’ve had a corrupt catalog that I thought it was worth giving some thought to.
My new strategy has changed slightly. I set Lightroom’s backup preference to once a week. Then I make sure I delete all prior backups (you don’t need ‘em). I continue on with my usual backup plan of backing up to Super Duper every night. So now Lightroom’s working catalog is backed up, Lightroom’s backup catalog is backed up (with full integrity check so I know it’s not corrupt), and my entire Mac is backed up too.
As a side note, that’s why I love this blog. It often takes on a life of it’s own. The comments, questions, answers, etc all have a huge part in feeding it and giving me plenty of things to think and talk about when it comes to Lightroom. And that all happens because of you. So thank you