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Petabytes on a budget: How to build cheap cloud storage

blog.backblaze.com

11–20 of 106 posts

Re: Petabytes on a budget: How to build cheap cloud storage

#11
effing love this.

I wonder what the reliability stats on this setup is, though. Is it really cheaper to jam all those drives in one unit without redundant PSU's, MB's, or a boot drive?

I'd guess you'd have to build at least 2 of these units and mirror them to get any sort of reliability. And, at that point, how long does it take to copy 58 TB across https?

data is hard.

Re: Petabytes on a budget: How to build cheap cloud storage

#12
post #3

I always thought it was best to focus on what I did best (application software) and leave the infostructure to others. Until I saw this: Raw Drives $81,000 Backblaze $117,000 Dell $826,000 Sun $1,000,000 NetApp $1,714,000 Amazon $2,806,000 EMC $2,860,000 I had no idea. Kinda makes one rethink what business they want to be in.

  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.

Re: Petabytes on a budget: How to build cheap cloud storage

#13
post #5

Great stuff. Would anybody care to clarify why access is through HTTPS and not HTTP? I presume all accesses to these pods are from within their data center? Or do they directly expose these boxes to clients (whoa!)?

BackBlaze runs online, off-site backups (like Mozy and Carbonite) at $5/month for unlimited storage. HTTPS is used to keep client data protected, I assume

Re: Petabytes on a budget: How to build cheap cloud storage

#14
post #11

effing love this. I wonder what the reliability stats on this setup is, though. Is it really cheaper to jam all those drives in one unit without redundant PSU's, MB's, or a boot drive? I'd guess you'd have to build at least 2 of these units and mirror them to get any sort of reliability. And, at that point, how long does it take to copy 58 TB across https? data is hard.

I would assume they don't care about any of the hardware, just the data. If you look at the setup, and how the drives are raided, there 45 drives are sub-divided into 15 raid arrays, of which it would take 3 to die before they lost data. Essentially, they would need 20% of their drives to die simultaneously for them to lose data.

Now, for the rest of the hardware, its not that important to if it fails. If one of the other components die, you're only looking at some down time (and a possible dead hard drive or two from a PSU dying, which I assume they monitor regularly). As long as the data is secure and in one piece, it doesn't really matter whether the pod is up or down, until someone needs the data. Just send out your repair guy to replace it and reboot it, and its fine.

Re: Petabytes on a budget: How to build cheap cloud storage

#15
post #7

67TB of storage, with 4GB of cache. I'd really love to see some performance numbers versus the way-too-expensive competition. If the systems are being used as tape drive replacements, I could see this working well, but as an actual NAS-like device, I can't imaging how it could perform acceptably. Of course, if those Intel motherboards have the dual 1Gb/s NICs that Intel boards generally do, it will probably take a wh…

http://www.wolframalpha.com/input/?i=(67+TB)+%2F+(2*(1+Gb%2F...)

It'll take 3 days at the theoretical max of the networking equipment to read/write the 67TB. The overhead of HTTPS constrains the networking so this is too low.

I'd expect that their internet connection (i.e. in/out of the data center) is the real bottleneck.

I believe that the system is being used as a tape drive replacement.

Re: Petabytes on a budget: How to build cheap cloud storage

#16
post #2

This is unbelievably awesome. Can you imagine what we could achieve if every company had this level of transparency?

Thinking the exact same thing! While technology isn't more than any typical hacker can slap together in their apartment (minus maybe the case fab), I think the application is ingenious and the full blog post about it, like dmillar, pointed out is rather awe-inspiring. And I was all happy because my new Core i7 box has 2TB of space and 6GB of ram... sigh That being said - did seagate ever fix their firmware issue on t…

I should think so - I have 4 of them in my ZFS pool, and scrubs are turning up no errors.

Re: Petabytes on a budget: How to build cheap cloud storage

#17
post #3

I always thought it was best to focus on what I did best (application software) and leave the infostructure to others. Until I saw this: Raw Drives $81,000 Backblaze $117,000 Dell $826,000 Sun $1,000,000 NetApp $1,714,000 Amazon $2,806,000 EMC $2,860,000 I had no idea. Kinda makes one rethink what business they want to be in.

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,…

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).

Re: Petabytes on a budget: How to build cheap cloud storage

#18
post #2

This is unbelievably awesome. Can you imagine what we could achieve if every company had this level of transparency?

Thinking the exact same thing! While technology isn't more than any typical hacker can slap together in their apartment (minus maybe the case fab), I think the application is ingenious and the full blog post about it, like dmillar, pointed out is rather awe-inspiring. And I was all happy because my new Core i7 box has 2TB of space and 6GB of ram... sigh That being said - did seagate ever fix their firmware issue on t…

I have the 500GB in the same series (with the corrupted firmware) and the fix did very nice things for it. Also, I have never had problems with the 7200.12 (the newer version of the same drive) in a 1TB model.

Re: Petabytes on a budget: How to build cheap cloud storage

#19
post #10

Wow. Do they offer S3-like storage? They should. If they can offer something like S3, but at one third of a penny per gigabyte per month (heck, let's splash out - a whole penny per gigabyte per month) I know quite a few people who'll be interested in talking to them... (including myself)

Apparently they use HTTPS for input/output using tomcat and some custom application.

That's a strange choice, HTTPS would incur quite a bit of overhead for something that is essentially a (large) drive at the end of a network cable used internally only. Why the encryption ?

quote from the article:

"A Backblaze Storage Pod isn’t a complete building block until it boots and is on the network. The pods boot 64-bit Debian 4 Linux and the JFS file system, and they are self-contained appliances, where all access to and from the pods is through HTTPS. Below is a layer cake diagram.

Starting at the bottom, there are 45 hard drives exposed through the SATA controllers. We then use the fdisk tool on Linux to create one partition per drive. On top of that, we cluster 15 hard drives into a single RAID6 volume with two parity drives (out of the 15). The RAID6 is created with the mdadm utility. On top of that is the JFS file system, and the only access we then allow to this totally self-contained storage building block is through HTTPS running custom Backblaze application layer logic in Apache Tomcat 5.5."

That's an odd choice for a storage server protocol stack.

Re: Petabytes on a budget: How to build cheap cloud storage

#20
Very interesting insight! I may try building a scaled-down version just for fun.

The cost comparison between raw drives, their custom solution, and Amazon S3, etc was a little skewed. S3 is designed for pay as you go storage so you're not paying for capacity you don't need. If you just need a few dozen gigabytes, it's a much better deal. If you need terabytes or a petabyte, a dedicated storage solution is more economical.

It's the same argument as vacation house vs timeshare. If you lived in a timeshare all year, it would cost more than buying the house.

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