The Backblaze Storage Pod Our secret to the least expensive cloud
storage in the world!
Offering both an unlimited online backup service and the world's least expensive cloud storage
service takes a lot of data storage. When Backblaze started out we needed a way to store our
customer's data inexpensively and safely. We developed the Backblaze Storage Pod as the key building
block of our cloud storage. Later we grouped 20 Storage Pods into a Backblaze Vault to optimize the
reliability and durability of the entire system.
A Storage Pod consists of 45, and now 60, hard drives in a 4U sized server made from commercially
available parts. Over the years we've introduced new and improved designs and with each new version we open-source the hardware design. That's right, anyone can build their own high capacity storage
server for as little as a nickel ($0.05) per Gigabyte, and many people have done exactly that.
Join the millions of people who have read how we've been making data storage affordable since 2009.
After the first blog post, a few resourceful people started building Backblaze
Storage Pods for themselves and began to send in pictures and stories of their home made pods. They
loved the fact that we published the parts list along with the instructions so they could modify
their pod to meet their unique needs. Even companies like Shutterfly and Netflix were inspired to
build their own storage pods.
Backuppods works closely with Evolve Manufacturing, our contract manufacturer for our
Storage Pods. The folks at Backuppods can sell you a
fully assembled Storage Pod chassis (without drives) and many of the other components needed to build a
version 4.5, 5.0 or 6.0 Storage Pod.
Protocase Inc. helped design Version 4.0 and prior Storage Pods. They also supplied
3.0 and Version 4.0 Storage Pods for Backblaze. Please check out www.45drives.com to
see the wide variety of products they offer inspired by Storage Pod 4.0 and prior designs.
One thing to know is that Backblaze does not sell Storage Pods, and since the design is open source we don’t provide support or warranty for anyone who chooses to build their own Storage Pods.
Storage Pods and Vault Pods
The Backblaze Storage Pod is just one part of building a cloud storage
In order to boot the machine you will need to have a software layer. Backblaze uses all free
software, Debian and Apache, to connect the pods to our network. Starting at the bottom, there
45 hard drives connected through SATA controllers. We then use the fdisk tool on Linux to create
partition per drive.
At this point a Storage Pod can have one of two personalities: an individual Storage Pod or a Backblaze Vault
Pod. For the individual Storage Pods we cluster 15 hard drives into a single RAID6
with two parity drives (out of the 15). The RAID Array is created with the mdadm
For Backblaze Vault Storage Pods each is one of 20 pods needed to create a Backblaze Vault. A
Backblaze Vault divides up a file into 20 pieces (17 data and 3 parity) and places a piece of
file on each of the 20 Storage Pods in the Vault. We use our own implementation of
Reed-Solomon to encode and distribute the files across the 20 pods, achieving 99.99999%
durability. We open-sourced our Reed-Solomon encoding implementation as well.
For both Storage Pods and Vault Pods, we use the EXT4 file system and only allow access to these totally self-contained systems through HTTPS running custom Backblaze application layer logic in Apache Tomcat. One of the most important
concepts here is that to store or retrieve data with a Backblaze Storage Pod or a
Backblaze Vault Pod, it is always through HTTPS. There is no iSCSI, no NFS, no SQL, no Fibre Channel. None of those technologies scales as cheaply, reliably, goes as big, nor can be managed as easily as pods with their own IP address
waiting for requests on HTTPS. We built our own software layer to monitor pod and vaults, decide where to store data and how to encrypt it, deduplicate it, and index it.
File System EXT4 Networking HTTPS Application Apache/ Tomcat