on ALL of the Storage Pod versions. Click Here.
It’s been over a year since Backblaze revealed the designs of our first generation (67 terabyte) storage pod. During that time, we’ve remained focused on our mission to provide an unlimited online backup service for $5 per month. To maintain profitability, we continue to avoid overpriced commercial solutions, and we now build the Backblaze Storage Pod 2.0: a 135-terabyte, 4U server for $7,384. It’s double the storage and twice the performance—at lower cost than the original.
In this post, we’ll share how to make a 2.0 storage pod, and you’re welcome to use the design. We’ll also share some of our secrets from the last three years of deploying more than 16 petabytes worth of Backblaze storage pods. As before, our hope is that others can benefit from this information and help us refine the pods. (Some of the enhancements are contributions from helpful kindred pod builders, so if you do improve your Backblaze pod farm, please balance the Karma and send us your suggestions!)
Quick Review – What makes a Backblaze Storage Pod
A Backblaze Storage Pod is a self-contained unit that puts storage online. It’s made up of a custom metal case with commodity hardware inside. You can find a parts list in Appendix A. You can also link to a power wiring diagram, see an exploded diagram of parts, and check out a half-assembled pod. The two most noteworthy factors are that the cost of the hard drives dominates the price of the overall pod and that the system is made entirely of commodity parts. For more background, read the original blog post. Now let’s talk about the changes.
Density Matters – Double the Storage in the Same Enclosure
We upgraded the hard drives inside the 4U sheet metal pod enclosure to store twice as much data in the same space. After the cost of filling a rack with pods, one datacenter rack containing 10 pods costs Backblaze about $2,100 per month to operate, roughly divided equally into thirds for physical space rental, bandwidth, and electricity. Doubling the density saves us half of the money spent on both physical space and electricity. The picture below is from our datacenter, showing 15 petabytes racked in a single row of cabinets. The newest cabinets squeeze one petabyte into three-quarters of a single cabinet for $56,696.
Our online backup cloud storage is our largest cost, and we are obsessed with providing a service that remains secure, reliable and, above all, inexpensive. We’ve seen competitors unable to react to these demands who were forced to exit the market, like Iron Mountain, or raise prices, like Mozy and Carbonite. Controlling the hardware design has allowed us to keep prices low.
We are constantly looking at new hard drives, evaluating them for reliability and power consumption. The Hitachi 3TB drive (Hitachi Deskstar 5K3000 HDS5C3030ALA630) is our current favorite for both its low power demand and astounding reliability. The Western Digital and Seagate equivalents we tested saw much higher rates of popping out of RAID arrays and drive failure. Even the Western Digital Enterprise Hard Drives had the same high failure rates. The Hitachi drives, on the other hand, perform wonderfully.