Also interesting is Facebook's handling of cold storage (2015).

From their blog post:

> The easiest way to protect against hardware failure is to keep multiple copies of the data in different hardware failure domains. While that does work, it is fairly resource-intensive, and we knew we could do better. We wondered, “Can we store fewer than two copies of the same data and still protect against loss?”

https://code.facebook.com/posts/1433093613662262/-under-the-...