^ I was asking more what the specifics drives you received, already had on them for running hours.
MTBF isn't significant in HDD lifespan expectations due to how it's calculated. It does tell a bit about quality control, as might the warranty (if the new purchase price were no higher), but really useless for any real world purpose. Have you ever owned ANY HDD that lasted 2.5M hrs running 24/7? Of course not. That's 285 years.
It would shed some light on infant mortality rates but you'd typically already be well past that period with a used drive.
Suppose it is only 1% of a 2.5M hr. MTBF, that puts it at almost 3 years old. If that's the case, the reality is that it is probably closer to 40% through its (average) lifespan, which may still be a good deal depending on how you look at it, but at that point, it's going to have a shorter remaining lifespan than the average new consumer grade HDD. It is a bit ironic but I'd rather pay a little more for a consumer grade HDD that has a longer expected remaining lifespan than a used enterprise drive.
Keep in mind that I'm stating this within the context of this topic, that the desire is to get a used 12TB HDD. That is a significant capacity still, and a lot of platters spinning for (years?) while data tends to show that higher capacity HDDs with more platters have higher failure rates. Personally, I wouldn't do it. The last thing I would do is buy a few years old drive with a lot of platters, enterprise or not.
Here's a bit dated article from Backblaze, but still interesting reading:
Last month I dug into drive failure rates based on the 25,000+ consumer drives we have and found that consumer drives actually performed quite well. Over
www.backblaze.com