Following the unfortunate demise of Jeff Atwood and Phil Haack’s blogs, the resultant schadenfreude on Reddit, and Jeff’s subsequent discussion of StackOverflow’s back-up process, I’m going to share with you everything that I know about back-up procedures. This won’t be a long post, I’m not a sysadmin.
You might keep frequent on-site back-ups to reduce the inconvenience of routine problems such as hardware failure, but it’s the off-site back-ups that ultimately determine how resilient you are in the face of real problems (fire, flood, etc.). In that final analysis only the off-site back-ups matter. Making more, or more frequent, on-site back-ups will not help if your off-site back-ups are non-existent, broken (a.k.a. untested), or not frequent enough. There’s really only one question you need to ask yourself when deciding how frequently you need to back-up: how much data am I willing to lose?
If you are taking fortnightly dumps off-site but three days of data loss would kill your business then your back-up plan is worse than useless. Sitting very still with all your fingers crossed would be a more effective disaster-prevention policy.