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Comment by frandroid | Hacker News Reader

The original poster was asking, if I can reword properly: Who is using enterprise-grade hard drives instead of consumer-grade ones, if FB doesn't (and why)?

Both consumer- and enterprise-grade hard drives use standard interfaces (SATA, etc) so all this "drivers" stuff you talked about doesn't apply to this particular hardware. Since even enterprise-grade hard drives will fail one day, one needs to have a proper backup strategy, which would backstop the needs of supporting of consumer-grade HDDs. So in light of this, why buy enterprise HDDs?

(I'm not saying one shouldn't, I'm just not buying the explanation above :])

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It is a lot like the pets vs cattle comparison. If your underlying structure can tolerate larger amounts of downtime the extra cost of enterprise equipment. For many applications it is easier to buy more expensive hardware that has exceptional uptime than it is to hire people to rewrite and take advantage of cloud based options.

Enterprise hard drives use SAS connectors to allow redundant paths and a full scsi command set. Enterprise hard drives have a bit error rate an entire order of magnitude better than consumer hard drives. The rated powered on hours and mean time between failure will be better, but not more cost effective with enterprise gear unless you take into account the labor cost and downtime cost of replacing that hardware.

I feel that explanation answers the question perfectly.

It's not about the fact that the hardware looks and interfaces the same, it's that it lasts longer, performs reliably and predictably and comes with support. Even if you design for failure, it's much better to have 1 drive fail than 3 in a system.

The enterprise stuff will just be more durable and usually more performant in every way so it's worth the cost, especially when most companies are not tech giants with all the engineering talent to build something like cold storage from the ground up. FB/Google/Amazon/Microsoft/Apple are very specialized high-tech companies who know how to do this and not representative of most "enterprise" customers.

If you are doing RAID, especially on a hardware RAID card consumer drives generally don't support TLER. This means a consumer drive will sit and try to read a bad sector again and again for long periods of time. You'll notice this on desktops when a drive is getting bad sectors that it will pause 30 or 40 seconds at a time. In a RAID setup it's better to fail fast and mark the drive bad for replacement, but the consumer drives don't send the hardware/OS the information it needs to do it quickly.

Most enterprise drives come off the exact same production line too.. Some have a different external interface but the important parts are all nearly the same, they might test them differently

Errr... no.

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