Chris Breen started the ball rolling by explaining Next up were and , each describing their personal backup plans. One theme that ran through all of these articles was that a lone backup is not sufficient. You should have at least two, ideally of different types (Time Machine, clones, cloud services, and so on).

For many Mac users, this is the equivalent of a dentist telling you that brushing your teeth is not sufficient; you also need to floss. And it's likely to be met with an equal lack of enthusiasm. After all, statistics have consistently shown that the majority of computer users have no backup plan at all. Two or three types of backups? Backups of backups? Forget-about-it!

But you shouldn't forget about it. I speak from personal experience. Multiple personal experiences. As one example, allow me to recount a recent incident that happens to involve one of the oddest and most distressing bugs I have yet to encounter.

A couple of weeks ago, while working with my Mac Pro, my Dock momentarily vanished. When it returned, most of its icons were gone. I had no immediate idea why this had happened. But I remained calm. I figured the fix was easy enough: go to the Applications folder and drag the desired icons back to the Dock.

I opened the Applications folder. It was at this point that I stopped being calm. My Applications folder was completely empty! Its contents had entirely vanished in less than a second. The missing files were not invisible, moved to another folder, dumped in the Trash, or otherwise recoverable in any way. They were gone--with a speed that I associate only with UNIX's fearsome rm command.