Hi Lawrence Oh man, I could write pages on this subject. I’ll try to keep it short though: Backblaze’s analysis is only really useful for home users and people in similar markets to the one Backblaze is (low-workload cloud storage). I equate these because most home users aren’t going to be doing significant workloads on their drives, and nor does Backblaze. BB’s workload is so light it can't really tax any drive from a workload POV, so their enterprise-vs-consumer analysis is not meaningful. This isn’t something they make clear at all. What the Backblaze posts do achieve for me is a good cross-vendor study of drive reliability for home use. It also suggests I should seriously consider using HGST enterprise drives at work, based on the relative reliability of the HGST consumer drives compared to the others. So if they could just stick to that, then I think their posts would be great, and would be doing a lot of good work. But they keep referring to their attempt at comparing consumer vs enterprise drives, and their methodology just doesn’t stack up. So they don't even begin to come close to convincing me that I should start using consumer drives instead of enterprise ones. If the other studies you refer to are the google and Schroeder ones from 2007, then they aren’t really relevant any more. I can go into this in more detail if you like, but I’ll leave it for now. I’m not aware of any other publicly reported large-scale disk drive health studies, so if you have something else then I’m keen to see it. SMART is also absolutely useful. The google study pointed this out in 2007, and their conclusion rings true now: SMART is great at telling you when a drive is failing or starting to fail. Some of the SMART indicators are very useful for this, for example the reallocated sector count: If this is increasing over time, then the drive is reallocating more sectors due to physical damage, and therefore the drive is failing. So SMART is fine for telling you a drive is *not healthy*. On the other hand, SMART is no use at telling you a drive is *healthy*: A clean bill of health today, according to SMART, doesn’t mean the drive won’t catastrophically fail tomorrow. This is the conclusion that the google paper drew, but a lot of people seem to misinterpret it.
BackBlaze have been frequently posting notes on their experience with running large numbers of hard drives in their storage service. Some salient points:
* “Enterprise” drives, while more expensive than “consumer” ones, are not significantly more reliable. (This has been borne out by other studies.) * Keep your drives running all the time, or switch them off when not in use? “Our vote is to keep them running.” * They do use SMART to keep an eye on their drives. Other studies I read reported that these only picked up a minority (around 30%) of failures, from which I concluded that SMART was not worth using. I suppose it’s different for these guys if it saves on costs to replace a drive *before* it actually starts reporting uncorrectable errors...