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Backblaze's 6 TB Hard Drive Face-Off

Esra Erimez writes: Backblaze is transitioning from using 4 TB hard drives to 6 TB hard drives in the Storage Pods they will be deploying over the coming months. With over 10,000 hard drives, the choice of which 6TB hard drive to use is critical. They deployed 45 and tested Western Digital (WD60EFRX) and Seagate (STBD6000100) hard drives into two pods that were identical in design and configuration except for the hard drives used.

6 of 173 comments (clear)

  1. Long story short (ad-less) by hcs_$reboot · · Score: 4, Informative

    - Initial reliability (how many drives failed) – No failures.
    - Running reliability (3 months) – No failures
    - SMART Stats (3 months) – No error conditions recorded for the 5 stats that we utilize.
    - Hard Drive Cost – about the same.
    - Energy Use – The Seagate drives were 7200 rpm and used slightly more electricity than the Western Digital drives which were 5400 rpm. This small difference adds up when you place 45 drives in a Storage Pod and then stack 10 Storage Pods in a cabinet.
    - Loading speed – Edge to Western Digital, by a little over 1 TB per day on average.

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    1. Re:Long story short (ad-less) by Solandri · · Score: 4, Informative

      - Energy Use â" The Seagate drives were 7200 rpm and used slightly more electricity than the Western Digital drives which were 5400 rpm. This small difference adds up when you place 45 drives in a Storage Pod and then stack 10 Storage Pods in a cabinet.
      - Loading speed â" Edge to Western Digital, by a little over 1 TB per day on average.

      That didn't really make sense to me that the 5400 RPM drive beat out the 7200 RPM drive, so I did a bit of research.

      The WD drives were the WD60EFRX. It's a 5-platter 6TB drive, or 1.2 TB/platter. It has 64MB cache.

      The Seagate drives were the STBD6000100. It's a 6-platter drive, or 1 TB/platter. It has 128MB cache. Googling for it brings up contradictory information, listing it as both 7200 RPM and 5900 RPM. (Note: It's pathetic that Seagate doesn't list basic information like RPM on their website.)

      So apparently the higher areal density on the WD (meaning more data can be written per rotation, and shorter r/w head strokes to move to a given number of cylinder tracks) is enough to overcome its RPM disadvantage. Given the results, it's likely the Seagate STBD6000100 is 5900 RPM drive, as 7200/5400 = 1.33 which would've exceeded the WD's higher areal density.

      I'd caution though that Backblaze's application seems to be a highly sequential task. Peak transfer rates were over 7 TB/day, which is more than 80 MB/s. Given the larger cache and higher RPM (whether 5900 or 7200), I'd expect the Seagate drive to perform better under random read/writes.

  2. Re:Meaningless by brianwski · · Score: 5, Informative

    Disclaimer: I work at Backblaze.

    > They've repeatedly published their research openly... just in case anyone cares.

    "Research" sounds too official, more like "observations in our environment", but THANK YOU for the kind words. What baffles me is why nobody else publishes these sorts of drive statistics. Why is Amazon silent? Why doesn't Google name drive names and failure rates? And if the answer is: "Google gets a great price on drives in exchange for their silence" then why hasn't Backblaze been offered a deal to keep quiet yet?! I'm serious, how big do you have to get before you get the better prices on drives? We essentially pay "retail".

  3. Re:Marketing by brianwski · · Score: 5, Informative

    Disclaimer: I'm an engineer at Backblaze.

    We do these drive statistics and observations originally for our own selfish internal reasons - this is information that is important for running our business. When we then release this kind of information, the info release is largely because it helps people hear about our company (and also maybe a little of "good for humanity" motivation thrown in there, we're Slashdot kind of people, we work in technology in Silicon Valley). But let me be clear: the information is as accurate as we can possibly make it, and we aren't pulling any punches and we aren't "in bed with" any drive manufacturers. I see this as a WIN-WIN. You get accurate and free information, and a few people hear our company name and look into what we do and maybe we gain a few customers. These posts are often written by the engineers working on the system and are trying to be as straight-forward and non-marketing as we can be.

  4. Re:Backups are not secure by brianwski · · Score: 5, Informative

    > Their backup scheme require them to have access to your private key (the one you encrypted your backup with).

    Disclaimer: I'm a Backblaze engineer who wrote a lot of that code.

    Your statement is a bit misleading, there are two levels of security in Backblaze. Data is always encrypted, and the "private key" is a totally standard OpenSSL PEM file that yes, we store for you. By default, this PEM file is secured by a passphrase that Backblaze knows, so your data is essentially only secured by your email address and password and you can recover your password by email. This is pretty light security (if somebody has access to your email they can recover your password), so it's best for backups of stuff you wouldn't mind too much if somebody got ahold of it, like say pictures of your cat. Don't laugh, I backup my public website on Backblaze servers, there is valuable data in the world that does not need encryption, that would be info you don't want to lose but is ALSO publicly readable.

    So if you are concerned at all about security, you can set your own personal "passphrase" on that PEM file that Backblaze absolutely never writes to disk - we don't store it. But if you do this you MUST remember that passphrase or your data is GONE. Without that passphrase, nobody will ever retrieve your data, not you, not the US government, not the NSA, NOBODY. You cannot "recover" that passphrase, and we don't know it. This is a good mode of security if you would be arrested on the spot for the contents of your files if the NSA got ahold of your data, because we really don't think it is breakable.

  5. Re:Meaningless by brianwski · · Score: 4, Informative

    > retail at the 10,000 drive order level

    You might be surprised how little discount we get. Our last purchase of 4 TByte Hitachi drives (960 drives in one purchase) we paid $135 each before tax and shipping. "B&H Photo" sometimes wins the bid (I don't know how or why), but you can basically get that same price within a couple bucks in units of 1 or 2 from their website. Note: we have no affiliation with B&H other than satisfied customers, and B&H do not win the bid every time.

    With that said, if anybody knows how to get more than $2 off "retail" please PLEASE let us know!!