Storage Pod 6.0: Building a 60 Drive 480TB Storage Server

By | April 25th, 2016

Storage Pod 6.0
Storage Pod 6.0 deploys 60 off-the-shelf hard drives in a 4U chassis to lower the cost of our latest data storage server to just $0.036/GB. That’s 22 percent less than our Storage Pod 5.0 storage server that used 45 drives to store data for $0.044/GB. The Storage Pod 6.0 hardware design is, as always, open source so we’ve included the blueprints, STEP files, wiring diagrams, build instructions and a parts list so you can build your very own Storage Pod. Your cost may be a bit more, but it is possible for you to build a 4U server with 480TB of data storage for less than a nickel ($0.05) a gigabyte – read on.

A little Storage Pod history

In 2009, Storage Pod 1.0 changed the landscape in data storage servers by delivering 67.5TB of storage in a 4U box for just $0.11/GB – that was up to 10 times lower than comparable systems on the market at the time. We also open-sourced the hardware design of Storage Pod 1.0 and companies, universities, and even weekend hobbyist started building their own Storage Pods.

Over the years we introduced updates to the Storage Pod design, driving down the cost while improving the reliability and durability with each iteration. Storage Pod 5.0 marked our initial use of the Agile manufacturing and design methodology which helped identify and squeeze out more costs, driving our cost per GB of storage below $0.05. Agile also enabled us to manage a rapid design prototyping process that allowed us stretch the Storage Pod chassis to include 60 drives then produce 2-D and 3-D specifications, a build book, a bill of materials and update our manufacturing and assembly processes for the new design – Storage Pod 6.0. All of this in about 6 months.

What’s new in Storage Pod 6.0

60 drive storage server

What’s new is 60 drives in a 4U chassis. That’s a 33 percent increase to the storage density in the same rack space. Using 4TB drives in a 60-drive Storage Pod increases the amount of storage in a standard 40U rack from 1.8 to 2.4 Petabytes. Of course, by using 8TB drives you’d get a 480TB data storage server in 4U server and 4.8 Petabytes in a standard rack.

When looking at what’s new in Storage Pod 6.0 it would easy to say it has 60 drives and stop there. After all, the Motherboard, CPU, memory, SATA cards, and backplanes we use didn’t change from 5.0. But expanding to 60 drives created all kinds of things to consider, for example:

  • How long do you make the chassis before it is too long for the rack?
  • Will we need more cooling?
  • Will the power supplies need to be upgraded?
  • Will the SATA cables be too long? The maximum spec’d length is 1 meter.
  • Can the SATA cards keep up with the 15 more drives? Or will we need to upgrade them?
  • Will the CPU and the motherboard be able to handle the additional data load of 15 more drives?
  • Will more or faster memory be required?
  • Will the overall Storage Pod be correctly balanced between CPU, memory, storage and other components so that nothing is over/under-spec’ed?
  • What hard drives will work with this configuration? Would we have to use enterprise drives? Just kidding!

Rapidly iterating to the right design

As part of the prototyping effort we built multiple configurations and Backblaze Labs put each configuration through its paces. To do this we assembled a Backblaze Vault with 20 prototype Storage Pods in three different configurations. Since each Storage Pod in a Backblaze Vault is expected to perform similarly, we monitored and detected those Storage Pods that were lagging as well as those that were “bored”. By doing this were were able to determine that most of the components in Storage Pod 6.0 did not need to be upgraded to achieve optimal performanace in Backblaze Vaults utilizing 60 drive Storage Pods.

We did make some changes to Storage Pod 6.0 however:

  • Increased the chassis by 5 ½” from 28 1/16” to 33 9/16” in length. Server racks are typically 29” in depth, more on that later.
  • Increased the length of the backplane tray to support 12 backplanes.
  • Added 1 additional drive bracket to handle another row of 15 drives.
  • Added 3 more backplanes and 1 more SATA card.
  • Added 3 more SATA cables.
  • Changed the routing to of the SATA-3 cables to stay within the 1-meter length spec.
  • Updated the pigtail cable design so we could power the three additional backplanes.
  • Changed the routing of the power cables on the backplane tray.
  • Changed the on/off switch retiring the ele-302 and replacing it with the Chill-22.
  • Increased the length of the lid over the drive bay 22 7/8”.

That last item, increasing the length of the drive bay lid, led to a redesign of both lids. Why?

Lids and Tabs

The lid from Storage Pod 5.0 (on the left above) proved to be difficult to remove when it was stretched another 4+ inches. The tabs didn’t provide enough leverage to easily open the longer drive lid. As a consequence Storage Pod 6.0 has a new design (shown on the right above) which provides much better leverage. The design in the middle was one of the prototype designs we tried, but in the end the “flame” kept catching the fingers of the ops folks when they opened or closed the lid.

Too long for the server rack?

The 6.0 chassis is 33 9/16” in length and 35 1/16” with the lids on. A rack is typically 29” in depth, leaving 4+ inches of Storage Pod chassis “hanging out.” We decided to keep the front (Backblaze logo side) aligned to the front of the rack and let the excess hang off the back in the warm aisle of the datacenter. A majority of a pod’s weight is in the front (60 drives!) so the rails support this weight. The overhang is on the back side of the rack, but there’s plenty of room between the rows of racks, so there’s no issue with space. We’re pointing out the overhang so if you end up building your own Storage Pod 6.0 server, you’ll leave enough space behind, or in front, of your rack for the overhang.

The cost in dollars

There are actually three different prices for a Storage Pod. Below are the costs of each of these scenarios to build a 180TB Storage Pod 6.0 storage server with 4TB hard drives:

How Built Total Cost Description
Backblaze $8,733.73 The cost for Backblaze given that we purchase 500+ Storage Pods and 20,000+ hard drives per year. This includes materials, assembly, and testing.
You Build It $10,398.57 The cost for you to build one Storage Pod 6.0 server by buying the parts and assembling it yourself.
You Buy It $12,849.40 The cost for you to purchase one already assembled Storage Pod 6.0 server from a third-party supplier and then purchase and install 4TB hard drives yourself.
These prices do not include packaging, shipping, taxes, VAT, etc.

Since we increased the number of drives from 45 to 60, comparing the total cost of Storage Pod 6.0 to previous the 45-drive versions isn’t appropriate. Instead we can compare them using the “Cost per GB” of storage.

The Cost per GB of storage

Using the Backblaze cost for comparison, below is the Cost per GB of building the different Storage Pod versions.

Storage Pod versions

As you can see in the table, the cost in actual dollars increased by $760 with Storage Pod 6.0, but the Cost per GB decreased nearly a penny ($0.008) given the increased number of drives and some chassis design optimizations.

Saving $0.008 per GB may not seem very innovative, but think about what happens when that trivial amount is multiplied across the hundreds of Petabytes of data our B2 Cloud Storage service will store over the coming months and years. A little innovation goes a long way.

Building your own Storage Pod 6.0 server

You can build your own Storage Pod. Here’s what you need to get started:

Chassis – We’ve provided all the drawings you should need to build (or to have built) your own chassis. We’ve had multiple metal bending shops use these files to make a Storage Pod chassis. You get to pick the color.

Parts – In Appendix A we’ve listed all the parts you’ll need for a Storage Pod. Most of the parts can be purchased online via Amazon, Newegg, etc. As noted on the parts list, some parts are purchased either through a distributor or from the contract assemblers.

Wiring – You can purchase the power wiring harness and pigtails as noted on the parts list, but you can also build your own. Whether you build or buy, you’ll want to download the instructions on how to route the cables in the backplane tray.

Build Book – Once you’ve gathered all the parts, you’ll need the Build Book for step-by-step assembly instructions.

As a reminder, Backblaze does not sell Storage Pods, and the design is open source, so we don’t provide support or warranty for people who choose to build their own Storage Pod. That said, if you do build your own, we’d like to hear from you.

Building a 480TB Storage Pod for less than a $0.05 per GB

We’ve used 4TB drives in this post for consistency, but we have in fact built Storage Pods with 5-, 6- and even 8-TB drives. If you are building a Storage Pod 6.0 storage server, you can certainly use higher capacity drives. To make it easy, the chart below is your estimated cost if you were to build your own Storage Pod using the drives noted. We used the lowest “Street Price” from Amazon or Newegg for the price of the 60 hard drives. The list is sorted by the Cost per GB (lowest to highest). The (*) indicates we use this drive model in our datacenter.
Storage Pod Cost per GB
As you can see there are multiple drive models and capacities you can use to achieve a Cost per GB of $0.05 or less. Of course we aren’t counting your sweat-equity in building a Storage Pod, nor do we include the software you are planning to run. If you are looking for capacity, think about using the Seagate 8TB drives to get nearly a half a petabyte of storage in a 4U footprint (albeit with a 4” overhang) for just $0.047 a GB. Total cost: $22,600.

What about SMR drives?

Depending on your particular needs, you might consider using SMR hard drives. An SMR drive stores data more densely on each disk platter surface by “overlapping” tracks of data. This lowers the cost to store data. The downside is that when data is deleted, the newly freed space can be extremely slow to reuse. As such SMR drives are generally used for archiving duties where data is written sequentially to a drive with few, and preferably no, deletions. If this type of capability fits your application, you will find SMR hard drives to very inexpensive. For example, a Seagate 8TB Archive drive (model: ST8000AS0002) is $214.99, making the total cost for a 480TB Storage Pod 6.0 storage server only $16,364.07 or a very impressive $0.034 per GB. By the way, if you’re looking for off-site data archive storage, Backblaze B2 will store your data for just $0.005/GB/month.

Buying a Storage Pod

Backblaze does not sell Storage Pods or parts. If you are interested in buying a Storage Pod 6.0 storage server (without drives), you can check out the folks at Backuppods. They have partnered with Evolve Manufacturing to deliver Backblaze-inspired Storage Pods. Evolve Manufacturing is the contract manufacturer used by Backblaze to manufacture and assemble Storage Pod versions 4.5, 5.0 and now 6.0. offers a fully assembled and tested Storage Pod 6.0 server (less drives) for $5,950.00 plus shipping, handling and tax. They also sell older Storage Pod versions. Please check out their website for the models and configurations they are currently offering.

Appendix A: Storage Pod 6.0 Parts List

Below is the list of parts you’ll need to build your own Storage Pod 6.0. The prices listed are “street” prices. You should be able to find these items online or from the manufacturer in quantities sufficient to build one Storage Pod. Good luck and happy building.

4U Custom Chassis
Includes case, supports, trays, etc.
Power Supply
EVGA Supernova NEX750G
On/Off Switch & Cable
Primochill 120-G1-0750-XR (Chill-22)
Case Fan
Dampener Kits
Power Supply Vibration Dampener
Soft Fan Mount
AFM03B (2 tab ends)
Supermicro MBD-X9SRH-7TF-O (MicroATX)
Intel XEON E5 -1620 V2 (Quad Core)
PC3-12800 DDR3-1600MHz 240-Pin
Port Multiplier Backplanes
5 Port Backplane (Marvell 9715 chipset)
2, 1
4-post PCIe Express (Marvell 9235 chipset)
2, 1
SATA cables RA-to-STR 1M locking
3, 1
Cable Harness – PSU1
24-pin – Backblaze to Pigtail
Cable Harness – PSU2
20-pin – Backblaze to Pigtail
Cable Pigtail
24-pin – EVGA NEX750G Connector
Screw: 6-32 X 1/4 Phillips PAN ZPS
Screw: 4-40 X 5/16 Phillips PAN ZPS ROHS
Screw: 6-32 X 1/4 Phillips 100D Flat ZPS
Screw: M3 X 5MM Long Phillips, HD
Standoff: M3 X 5MM Long Hex, SS
Foam strip for fan plate – 1/2″ x 17″ x 3/4″
Cable Tie, 8.3″ x 0.225″
Cable Tie, 4″ length
Plastic Drive Guides
Label,Serial-Model,Transducer, Blnk


  • May be able to be purchased from, price may vary.
  • Sunrich and CFI make the recommended backplanes and Sunrich and Syba make the recommended SATA Cards.
  • Nippon Labs makes the recommended SATA cables, but others may work.
  • Sold in packages of 100, used 100 package price for Extended Cost.


Andy Klein

Andy Klein

Director of Product Marketing at Backblaze
Andy has 20+ years experience in technology marketing. He has shared his expertise in computer security and data backup at the Federal Trade Commission, Rootstech, RSA and over 100 other events. His current passion is to get everyone to back up their data before it's too late.
Category:  Cloud Storage
  • Mayuresh Paradkar

    Can I use 10 or 12 TB drives instead?

  • Brian Swift

    Very cool topic. I’d assume most of your backup product data is quite cold. Curious if you’ve analyzed the cost of keeping drives near-line, with robotic access to bring a cold “tome” online when needed for a restore.

  • Thomas Weihert

    I have some questions on the future of storage pods:
    * Have you ever thought about constructing them without powersupply and instead build a large, single (but redundant) powersupply into the rack itself?
    * And if, what are the reasons for it or against? Especially:
    – would it reduce or increase costs?
    – would it reduce or increase power consumption? (because of efficency while transforming current),
    – would there be positive or negative effects on cooling or airflow?

    I am sure there are more interesting questions and I would like to read, if you have some findings on this issue.

  • Brice Fleckenstein

    I am curious what model of PS you folks plan to move your Pod 6.0 design to once the existing supply of the “out of production” EVGA G2 power supply dries up.
    I don’t trust their new G3 model as it moved to a SLEEVE BEARING fan design….

    Also, it appears that the motherboard you spec for the 6.0 pod is no longer in production – have you figured out a new option to go to there yet?

    Have you been working with the Seagate or HGST SMR drives yet? pricing has come down a LOT on them, to the point that the Seagate 8TB and 6TB archive drives are the lowest-cost on the market by quite a bit per TB (except for some of the external backup drives, that I suspect use the SAME drive mechanism).

  • Кирило Хацько

    it’s time to show 7.0

    • Scott

      Uh yeah…I’ve been following this since SP 1.0 and am really keen on seeing what their latest design is all about. In all the years that have elapsed since the beginning I have yet to find ANYONE who manufactures/sells a SATA 3.0 adapter (not SAS) with 2 PCIe lanes per port (the proper amount of lanes necessary to carry ALL SATA 3.0 traffic possible). Now the Backblaze guys may not need this bandwidth TO THE CLOUD, but I bet they sure could use it when doing internal provisioning and copying. *I* could use this, but can’t find it. The best I could muster is finding offerings (and even these are scant) that have 1 lane per port.

  • Sorry, duplicate post.

  • Are the rails used to mount the pod into a server custom made? Or standard off the shelf? Curious about mounting a 4U server with this much weight. Would appreciate a link to the ones used, if available.

  • Matt

    Seagate have announced 60GB SSD’s in 3.5″ form factor. That’s crazy. I wonder what pricing they will announce.

    • Brice Fleckenstein

      I forget where I saw the price but it was WAY WAY crazy high, suitable for very narrow usages (Eve Online might be able to justify the pricing, for example).

  • Chris Moore

    Are you converting the existing inventory over to the new design?
    How many new pods are being elevated in a given time-frame?

  • Hlini

    Does anyone know if is not taking orders anymore? Trying to contact them through email but not getting any replies and there is no phone number listed.

  • Joshua Adkisson

    Is it possible to add a hot spare now? Also, will the drives be hot swappable…? Technically it’s available in the kernel of most modern linux distros…but is it hardware supported…

  • Arie

    I Want to make this backblaze with my own but where i can get some parts that still available because in backup pods i have to buy all part. i just need backplane, or mini sas ti sata with screw mounting and sata card

  • oprex

    Where can I buy those items? I can not find any place that sells the backplane.

  • Chris Moore

    I am sure that you get some sort of volume discount from, but they list the price of the configured unit (no drives) at $ 5,950.00… You can get a SuperMicro SERVER 6048R-E1CR60N configured with two six core Xeon E5 processors and 32 GB of RAM at retail for $6,828 and if you worked a deal with SuperMicro I am sure you could get a better price, much closer to your solution.
    The thing is, I am not sure you are really saving that much money building your own hardware. You are certainly paying to reinvent the wheel and I have used these SATA port multipliers and I can’t see how they are reliable for you. What kind of failure rate to you have from them and how much does it cost you in performance?

  • Jose Barahona

    do you have a system recomendation for one of this? o some tutorial.

  • kingmouf

    I have been noticing that 2.5 inch 4TB drives have been showing up as external drives with pretty competitive prices (compared to 3.5 inch drives). I am wondering whether you have considered using such drives, given the fact that you could probably squeeze more drives in such a storage box and the power consumption of the overall system could be lower.

  • trey

    at least if you build your own pod you cause use it with linux!

  • David Ritchie

    Had a couple of questions. For your configuration, what is typical power consumption and weight for a loaded unit?

  • Jesper Monsted

    Why the ancient motherboard and CPU? Are they leftovers from old pods or are they just thoroughly tested and are fast enough for your use?

    • Andy Klein

      The motherboard and CPU work for us for the purpose at hand, storing data. Other folks have built their own Pods with faster components as a single system is more likely to get overloaded, whereas we spread the load over many systems, hence less horsepower needed on a per system basis.

  • Patrick

    What kind of thoughput do you get per pod?

  • Mark Scudder

    So, okay, help me out here. If I built one of these for my home or business, or bought one from Backuppods, I would have to run CrashPlan on it to use it for its intended purpose. Because the reason I left Backblaze is that you didn’t offer a local backup server option or Linux support. It seems really stupid to me to build a Backblaze Storage Pod and then have to run CrashPlan on it because you only support UNIX-like server operating systems and backup servers internally. So why would I buy one of these just to put a competitor’s software on it?

    • Andrew Weisz

      You are missing the point. This is just a detailed way of getting 60 drives into a 4u chassis.

      You can run whatever OS you want. Whatever software. Whatever filesystem.

      They aren’t selling a backblaze pod. They are selling a really dense storage box.

    • Hi Mark, you can use whichever OS you like on it. Plus you can write scripts or use one of our integrators to back up that pod to, our new service.

      • Chris Moore

        You are missing the point. How about supporting the backup of Linux or BSD Unix clients?

        • Nothing to report at the moment. But you can use HashBackup with Backblaze B2, they have a great client that works with Linux!

          • disqus_8evUIphm4F

            Is there any HashBackup equivalent that is open sourced? Also, HashBackup doesn’t run on Windows. Any option for Windows? Or backing up VmWare to BackBlaze B2, open sourced or otherwise?

  • Thibault Molleman

    What’s the current total amount of petabytes that you guys store?

  • Andy Klein

    Point of clarification on the “rack discussion”. Our cabinets are 39″ deep, and are 29″ post to post in depth. This distance was set for version 5.0 Storage Pods and older. If you have an Open Rack at 29″, then Storage Pod 6 will be longer than the rack. Of course, if you have a 39″ cabinet, then Storage Pod 6 will fit nicely inside.

  • iansltx

    Typo in the chart halfway through: the 6.0 pod is 240TB, not 180 :)

    Nice job stacking in more storage, btw. Will be interesting to ee when, if ever, SMR makes more sense for y’all. Just got an 8TB external using the tech and, while sequential writes are fast, let’s just say I’m glad its primary purpose is being a Time Machine backup…

    • Yea, we are working on fixing that :D