Patrick sent me this and I thought it was interesting:
At Backblaze, we provide unlimited storage to our customers for only $5 per month, so we had to figure out how to store hundreds of petabytes of customer data in a reliable, scalable way—and keep our costs low. After looking at several overpriced commercial solutions, we decided to build our own custom Backblaze Storage Pods: 67 terabyte 4U servers for $7,867.
In this post, we’ll share how to make one of these storage pods, and you’re welcome to use this design. Our hope is that by sharing, others can benefit and, ultimately, refine this concept and send improvements back to us. Evolving and lowering costs is critical to our continuing success at Backblaze.
Petabytes on a budget: How to build cheap cloud storage | Backblaze Blog