SMART testing has been around for a while and isn’t very well understood. I can’t say that I’m an expert on it, but I’ve come to have several fairly well developed ideas in regards to it. First off, if I have a live hard drive that fails to complete a SMART test, it’s time for me to retire that drive. It may seem extravagant, but I would rather not have to spend loads of time recovering data of a potentially failing drive. It’s true that SMART is not necessarily going to raise a red flag before a significant data loss event happens. In fact, I’ve seen drives report that they’ve passed the health test in spite of some serious disk problems. What I think you ought to look out for are a few of these points: