Backblaze datacenter had 56, 224 spinning hard drives containing customer data. These hard drives reside in 1, 249 Backblaze Storage Pods. By comparison 2015 began with 39, 690 drives running in 882 Storage Pods. We added 65 Petabytes of storage in 2015 give or take a Petabyte or two. Not only was 2015 a year of growth, it was also a year of drive upgrades and replacements. Let’s start with the current state of the hard drives in our datacenter as of the end of 2015 and then dig into the rest later on.