By now, the fact that disk drives fail a lot more than the vendors say they should, and for different reasons than we used to think, should be old news. However, it’s been on my mind a lot lately, as in the last three months I’ve lost two drives, and a third is starting to fail. Coincidentally, all three are Maxtor DiamondMax 10 drives, one 150 GB and two 300 GB, all SATA150. They are all well within their design life (and warranty); they have all operated well within their environmental limits; there is no reason why three out of the six Maxtor drives I have should fail in such rapid succession, while all my Western Digital drives – some of them twice as old – are fine. In fact, I’ve never lost a Western Digital drive; on the other hand, all the IBM drives I’ve had are toast, as is the only Seagate I ever bought, a Barracuda that was pretty much DOA, though I misidentified the problem and let the disk lie on a shelf while the warranty ran out.
It also makes me think about the disconnect between the advertised MTBF and the actual warranty. Remember that the MTBF is determined by engineers and marketeers, while the length of the warranty is decided by bean counters who above all want to make sure they don’t spend more money shipping replacements than they made selling the original drives. Long warranties help sales, but when your RMA rate exceeds your profit margin, your shareholders are going to come knocking on your door with torches and pitchforks.
So what I’m thinking here is, the engineers and marketeers are full of hot air (well, maybe not the engineers, but in my experience they tend to get overridden by the marketeers), but the bean counters probably know what they’re doing.
Still, numbers like these make you wonder. How much do you want to bet that the data sheets for these models all quote seven-digit MTBFs, or annualized return rates of less than 1%?