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Comment by cperciva | Hacker News Reader

  Backblaze      $117,000
  [...]
  Amazon       $2,806,000

I cry foul. Backblaze's "67 TB" pods actually only hold 58.5 TB, so their hardware cost per PB of storage is $134k, not $117k; and that's without any high-level redundancy. Servers fail -- both catastrophically, and by silently corrupting bits -- and Backblaze's $134k / PB doesn't have any protection against that. Datacenters also fail -- power outages, cut fibre, FBI raids, etc. -- and any system which stores all of its data in a single datacenter lacks any protection against that. Store each file on two different servers in each of two different datecenters, and suddenly Backblaze's $134k turns into $536k. The price for Amazon, in contrast, is based on the assumption that their prices remain fixed for the next 3 years -- which seems a rather radical assumption.

Is backblaze's solution cheaper than S3? Absolutely. But they're also twisting the numbers a bit.

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Interesting, but Amazon doesn't guarantee most of those things. They guarantee a 99.99% uptime, but that isn't counting a complete datacenter failure. In fact, it sounds to me as if they have a similar set up to the backblaze people.

99.99% uptime means roughly 1 hour per year of downtime. I don't know what the specific failure rates on the components are, but it seems reasonable that A) the data drives are hot-swappable, and will not cause downtime when they are replaced and B) the rest of the components fail once a year (or less) and take ~10 minutes to replace and reboot the system. With 4 main places of failure (PSU, Boot Drive, Motherboard/Ram/CPU, Drive controllers), as long as you have staff constantly on call and they can respond within 5 minutes of a failure, 99.99% uptime seems reasonable.

I don't know where you got the idea that your data was on 4 different servers when using S3. I can't find even the slightest amount of information on that. Yes, that would be nice, and it is cool to think that, but its rather doubtful that they're actually doing that (or they could probably add another 9 to their uptime).

>but that isn't counting a complete datacenter failure

I believe that S3 replicates to multiple physical locations. So, while you might experience downtime, you probably won't experience data loss.

Re. geographical redundancy, see comment http://news.ycombinator.com/item?id=422574 :

"Amazon keeps at least 3 copies of your data (which is what you need for high reliability) in at least 2 different geographical locations. "

I can't find the original source supporting that statement, but I also know it to be true based on direct contact with AWS team. (I'm using AWS since private alpha of EC2 in 2005)

I can't find that anywhere either, and would be interested in seing it. In fact, all I can find is: A bucket can be located in the United States or in Europe. All objects within the bucket will be stored in the bucket’s location, but the objects can be accessed from anywhere. which seem to imply that your data is located in one location, not 2.

In addition, looking at the actual S3 contract, they're really only guaranteeing at 99.9% uptime, which allows for up to 8 hours of downtime a year, more than enough to completely re-build the outer server once a year, as long as they can keep the data intact (which they seem more than capable of with their setup, once again assuming their data center is not completely destroyed).

Another thing that they aren't taking into account over S3 is power costs, physical datacenter rent costs, and bandwith hookup. Still its probably a lot cheaper but important to note that they are comparing apples and apple cider.

On their graph it says they subtracted data center costs from the price of S3.

what does s3 charge for transfer? $0.10 per gigabyte? I bet that covers much of the data center costs.

That's just the cost of hardware. How much more do you think it would cost if they included all their research and development, installation and assembly hours, etc?

That is just the cost to buy all the components they have. If you budgeted that in you'd just have a bunch of boxes at your office that weren't even wired up. On the other hand, from Dell or Sun you at least have all the hardware in the chassis, if not some basic configuration and OS install done for you. Go with Amazon and you've already got it racked up in a data center with dedicated techs and replacement parts on hand.

It isn't a fair comparison.

So you're currently paying $800k+ per box to install Solaris?

Tell you want, since you're a fellow HNer, I'll save you some money and do it for half that. I'll even throw in some basic configuration. You're welcome!

It really depends on what they ascertained their needs as. Perhaps they don't feel they need the additional protection, or they have another backup scheme in mind. If their solution works for them (which is seems to) then indeed, for their needs at least, the cost comparison is pretty accurate.

It might not add up the same for your needs (assuming you want multi-data center redundancy of all data, etc...).

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